Determine the moisture level or lipid level of the skin

Abstract

A system (100) and method for determining the moisture level or lipid level of skin is provided. The system (100) includes at least two electrodes (108) adapted to contact the skin and a signal generator (106) configured to generate an electrical signal at a frequency across the at least two electrodes (108). The system (100) is configured to measure the conductivity between the at least two electrodes (108). The system (100) is further configured to determine the moisture level or lipid level of the skin based on the measured conductivity and the frequency of the electrical signal.

Description

Technical Field

[0001] The present invention relates to systems and methods for determining the moisture level or lipid level of the skin. Background Art

[0002] Skin surface lipid (e.g., sebum) and water (e.g., hydrate) levels are considered important factors in determining skin appearance and skin health. The proper balance between these components is indicative of healthy skin and plays a central role in protecting and maintaining skin integrity. The hydrate and lipid retention capacity of the skin is primarily associated with the stratum corneum (SC). The SC acts as a barrier to water loss and is composed of a bilayer matrix of corneocytes and intercellular lipids. The water retention properties of the SC depend on (i) the presence of natural hygroscopic agents, collectively referred to as natural moisturizing factors (NMFs), and (ii) the SC intercellular lipids that are organized to form a barrier to prevent transepidermal water loss.

[0003] Typically, the skin remains elastic when it contains 10-20% moisture, but becomes fragile when it is reduced to less than 10%. Skin lipids (e.g., sebum) are a mixture of fatty acids, triglycerides, proteins, and other molecules produced by sebaceous glands in the dermis. Skin lipids keep the skin smooth and elastic by sealing and retaining moisture in the corneal layer and preventing evaporation and bacterial infection. Sebum excretion rate (SER) reflects the production of lipids (e.g., sebum) and is closely related to the physiological activity of sebaceous glands. This is important information in the pathogenesis of sebaceous gland diseases and papules and acne.

[0004] An optimal balance between lipid levels and moisture levels provides the skin with a radiantly smooth texture and natural-looking pigmentation, which is important from a cosmetic perspective. Excessive lipid production can lead to clogged pores, which can cause blotchiness. Adequate amounts of skin hydration and lipids can make the skin appear smooth, soft and supple, while insufficient moisture can cause the skin to appear dull and cracked, appearing older. A reduction in the efficiency of the skin's barrier and moisture retention functions can result in rough skin that is prone to dryness, which can potentially make it more susceptible to the risk of infection.

[0005] PCT patent application WO 2016 / 208932 A1 discloses a skin condition measuring device that is configured to measure skin moisture and skin oiliness by applying an alternating current to the skin and measuring the return alternating current. According to the patent application, skin moisture can be derived from the measured resistance, and skin oiliness can be derived from the shape of the measured return alternating current. It is claimed that skin moisture and skin oiliness can be derived from only one input signal. Summary of the invention

[0006] As described above, moisture and lipid content are important factors in determining overall skin health, and there are hydrate measurement devices that measure, for example, the capacitance or conductivity of the skin and detect moisture on the skin based on these measurements. However, the inventors have observed that these measurements may actually depend on the moisture (e.g., hydrate) level and lipid (e.g., oil) level of the skin, which may lead to inaccuracies in such devices. For example, even if two pieces of skin with the same hydration level are measured, the hydration level measured with such a device may vary depending on the surface lipid level of the skin. Therefore, it is desirable to provide systems and methods for determining the level of moisture or lipid content of the skin.

[0007] According to a first aspect, there is provided a system for determining the moisture level or lipid level of the skin as defined in claim 1. Advantageous embodiments are defined in claims 2-10.

[0008] The system includes at least two electrodes adapted to contact the skin and a signal generator configured to generate an electrical signal at a frequency across the at least two electrodes. The system is configured to measure conductivity between the at least two electrodes and determine the moisture level or lipid level of the skin based on the measured conductivity and the frequency of the electrical signal.

[0009] The signal generator may be configured to generate an electrical signal at a first frequency in a first frequency range. The system is configured to determine the moisture level of the skin based on the measured conductivity when the frequency of the signal is the first frequency.

[0010] In some embodiments, the first frequency range may be a frequency range from 10 kHz to 100 kHz or a frequency range from 0.8 MHz to 5 MHz.

[0011] In some embodiments, the first frequency may be 50 kHz or 1 MHz.

[0012] The signal generator is configured to generate an electrical signal at a second frequency in a second frequency range. The system may be configured to determine the lipid level of the skin based on the measured conductivity when the frequency of the signal is the second frequency.

[0013] In some embodiments, the second frequency range may be different from the first frequency range.

[0014] In some embodiments, the second frequency range may be a frequency range from 10 Hz to 500 Hz or a frequency range from 10 MHz to 100 MHz.

[0015] In some embodiments, the second frequency may be 50 Hz or 50 MHz.

[0016] In some embodiments, the system can be configured to measure conductivity at multiple frequencies to obtain multiple conductivity measurements.

[0017] In some embodiments, the system can be configured to determine the moisture level or lipid level of the skin by determining an average moisture level or lipid level of the skin from a plurality of conductivity measurements.

[0018] In some embodiments, the system can be further configured to compare the measured conductivity to one or more predefined curves that describe how skin conductivity changes with frequency, and to determine the moisture level or lipid level of the skin based on the comparison of the measured conductivity and the frequency of the radio frequency signal.

[0019] In some embodiments, the system may be further configured to determine skin condition based on the determined moisture level or lipid level.

[0020] In some embodiments, the system may be further configured to determine a recommendation for skin treatment based on the determined skin condition.

[0021] According to a second aspect, there is provided a method for operating a system to determine the moisture level or lipid level of the skin as defined in claim 11.

[0022] The system includes at least two electrodes adapted to contact the skin and a signal generator configured to generate an electrical signal at a frequency across the at least two electrodes. The method includes measuring conductivity between the at least two electrodes and determining a moisture level or lipid level of the skin based on the measured conductivity and the frequency of the electrical signal.

[0023] According to a third aspect, there is provided a computer program product comprising a non-transitory computer readable medium having computer readable code embodied therein, the computer readable code being configured to, when executed by a suitable computer or processor, cause the computer or processor to perform the method as described above.

[0024] According to the aspects and embodiments described above, by considering the frequency of the electrical signal when determining the moisture level or lipid level according to the measured conductivity, the moisture level of the skin can be measured substantially independently of its lipid level, and / or the lipid level of the skin can be measured substantially independently of its moisture level. More specifically, by determining the moisture level or lipid level based on the measured conductivity and the frequency of the electrical signal, the conductivity measurement can be performed at a frequency that is more sensitive to the measured property (e.g., moisture level or lipid level). In this way, a more accurate measurement value of the moisture level or lipid level of the skin can be determined. Moreover, a single system (e.g., a single device) can be used to determine the moisture level and lipid level of the skin. The system and corresponding method can be used to achieve a balance between the assessment of moisture level and lipid level, which is related to skin health and can therefore be used to select appropriate skin care treatments and products. The system and method can also be used to monitor the progress of such treatments.

[0025] These and other aspects will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Exemplary embodiments will now be described, by way of example only, with reference to the following drawings, in which:

[0027] Figure 1 is a diagram of a system according to an embodiment of the present invention;

[0028] Figure 2 A graph showing frequency versus skin conductivity for different skin types is shown;

[0029] Figure 3 The ratio of conductivity comparing the conductivity of different skin types with respect to frequency is plotted;

[0030] Figure 4 A table showing exemplary frequency ranges for determining lipid levels and moisture levels of skin according to some embodiments;

[0031] Figure 5 depicts relative lipid levels and moisture levels of different skin types according to an embodiment;

[0032] Figure 6 depicts relative lipid levels and moisture levels for various skin conditions according to an embodiment; and

[0033] Figure 7 is a flow chart of an example of a method for operating a system to determine moisture level or lipid level of skin according to an embodiment. DETAILED DESCRIPTION

[0034] As described above, systems and methods are provided for determining the level of moisture (or hydrate) or lipid (or sebum or oil) content of the skin.

[0035] Figure 1 A system 100 for determining the moisture level or lipid level of the skin is shown. The system includes at least two (e.g., at least one pair) electrodes 108 and a signal generator 106, the at least two electrodes 108 being adapted to contact the skin, the signal generator 106 being configured to generate an electrical signal at a frequency across the at least two electrodes 108. In some embodiments, the system 100 described herein may be an apparatus. Briefly, the system 100 is configured to measure the conductivity between the at least two electrodes 108 and determine the moisture level or lipid level of the skin based on the measured conductivity and the frequency of the electrical signal. In use, the at least two electrodes and the skin form an electrical circuit. Therefore, the electrical signal generated across the at least two electrodes 108 passes through the skin between the at least two electrodes 108, so that the conductivity of the skin can be measured.

[0036] In some embodiments, the at least two electrodes 108 may include at least one active electrode and at least one corresponding return electrode, the at least one active electrode being configured to emit an electrical signal, the at least one corresponding return electrode being configured to receive an electrical signal emitted from the at least one active electrode. In some embodiments, the at least two electrodes 108 may include at least two microelectrodes. One of the at least two electrodes 108 may be positioned at any suitable distance from another of the at least two electrodes 108. For example, in some embodiments, the electrodes may be positioned at a distance in the range of 0.1 mm to 1 mm from each other. In this way, the sensitivity of the system 100 may be increased, such as to measure the superficial layer of the skin.

[0037] As described above, the inventors have observed that the conductivity of the skin can depend on both the moisture level and the lipid level, which can lead to inaccurate hydration level measurements obtained using existing equipment. By determining the moisture level or lipid level based on the measured conductivity and the frequency of the electrical signal, conductivity measurements can be made at a frequency that is more sensitive to the property being measured (e.g., moisture level or lipid level). In this way, a more accurate measurement of the moisture or lipid content of the skin can be determined.

[0038] Those skilled in the art will be familiar with electrodes suitable for contacting the skin. In some embodiments, the pad (or patch) may include at least two electrodes 108, and the pad may be suitable for contacting the skin. For example, each electrode may be partially embedded in the pad. In some embodiments, the at least two electrodes 108 (or a pad including at least two electrodes 108) may include an adhesive surface that enables the at least two electrodes 108 (or a pad including at least two electrodes 108) to adhere to the skin. In some embodiments, the at least two electrodes 108 may include an electrode array. In some embodiments, the at least two electrodes 108 (or electrode array) may be configured (or arranged) to cover an area of ​​interest on the skin. For example, the electrode array may be used to measure the conductivity of a large area of ​​skin so as to map the skin condition over a large area. In some embodiments, the electrode array may be included in, for example, a fingerprint sensor.

[0039] As mentioned earlier, the signal generator 106 of the system 100 is configured to generate an electrical signal at a frequency across at least two electrodes 108. In some embodiments, the signal generator 106 can be configured to generate frequency pulses. The frequency pulses can be, for example, fixed frequency pulses or variable frequency pulses. In some embodiments, the pulses can include low voltage pulses. In some embodiments, the signal generator 106 can be configured to generate radio frequency (RF) signals. Therefore, in some embodiments where the signal generator 106 is configured to generate frequency pulses, the pulses can include radio frequency pulses.

[0040] like Figure 1 As shown, in some embodiments, the system 100 may further include an amplifier 110 (such as a radio frequency amplifier). In some embodiments, the amplifier 110 may amplify the voltage output by the signal generator 106. Figure 1 As shown, in some embodiments, the system 100 may also include a conductivity measurement system (such as an impedance measurement system) 112. The conductivity measurement system 112 may, for example, measure a voltage across the at least two electrodes 108. When the at least two electrodes 108 are in contact with the skin (e.g., when the system is in use), the conductivity measurement system 112 may measure the current flowing through the circuit formed by the at least two electrodes 108 of the system 100 and the skin. The conductivity measurement system 112 may be configured to measure the conductivity between the electrodes based on the measured current. Those skilled in the art will appreciate the manner in which the conductivity may be derived from the measured current.

[0041] In some embodiments, the system 100 can be implemented mechanically, for example, the conductivity measured between the electrodes can be displayed on an analog display. Such an analog display can be calibrated (for example, the scale can be moved or scaled) so that the analog display displays the moisture level or lipid level.

[0042] In other embodiments, Figure 1 As shown, the system 100 can also include a processor 102. The processor 102 can, for example, be configured to control the signal generator 106 to generate an electrical signal at a frequency across at least two electrodes 108. For example, the processor 102 can be adapted to control the signal generator 106 to generate pulses of a desired frequency, voltage, and / or pulse duration. In some embodiments, the conductivity measurement system 112 can be controlled by the processor 102. Alternatively or in addition, in some embodiments, the output of the conductivity measurement system 112 can be sent to the processor 102 for subsequent processing and / or output (e.g., display to a user).

[0043] Typically, in embodiments where the system 100 includes a processor 102, the processor 102 can control the operation of the system 100 to implement the methods described herein. The processor 102 can be implemented in a variety of ways using software and / or hardware to perform the various functions described herein. In a particular embodiment, the processor 102 may include a plurality of software and / or hardware modules, each of which is configured to perform or be used to perform a single or multiple steps of the methods described herein. The processor 102 may include one or more processors (such as, one or more microprocessors, one or more multi-core processors, and / or one or more digital signal processors (DSPs)), one or more processing units and / or modules, and / or may be configured or programmed (e.g., using software or computer program code) to control or operate the system 100 in a manner described herein One or more controllers (such as, one or more microcontrollers).

[0044] In some embodiments, for example, the processor 102 may include multiple (e.g., interoperable) processors, processing units and / or modules, multi-core processors, and / or controllers configured for distributed processing. Those skilled in the art will appreciate that such processors, processing units and / or modules, multi-core processors, and / or controllers may be located in different locations and may perform different steps of the methods described herein and / or different parts of a single step. The processor 102 may be implemented as a combination of dedicated hardware that performs some functions (e.g., amplifiers, preamplifiers, analog-to-digital converters (ADCs), and / or digital-to-analog converters (DACs)) and processors that perform other functions (e.g., one or more programmed microprocessors, controllers, DSPs, and associated circuits).

[0045] like Figure 1As shown, in some embodiments, system 100 may include memory 104. Memory 104 may include instruction data representing an instruction set. For example, memory 104 may be configured to store instruction data in the form of program code that can be executed by processor 102 so that system 100 operates in the manner described herein. In some embodiments, instruction data may include multiple software and / or hardware modules, each of which is configured to perform or be used to perform a single or multiple steps of the method described herein. In some embodiments, memory 104 may be part of a device that also includes one or more other components of system 100 (e.g., processor 102 and / or one or more other components of system 100). In alternative embodiments, memory 104 may be part of a device separate from other components of system 100.

[0046] In some embodiments, the memory 104 may include multiple sub-memories, each of which is capable of storing an instruction data. In some embodiments where the memory 104 includes multiple sub-memories, the instruction data representing the instruction set may be stored in a single sub-memories. In other embodiments where the memory 104 includes multiple sub-memories, the instruction data representing the instruction set may be stored in multiple sub-memories. For example, at least one sub-memories may store instruction data representing at least one instruction of the instruction set, while at least one other sub-memories may store instruction data representing at least one other instruction of the instruction set. Therefore, according to some embodiments, instruction data representing different instructions may be stored in one or more different locations in the system 100. In some embodiments, the memory 104 may be used to store information, data, signals (e.g., conductivity signals), and measurements (e.g., conductivity measurements) acquired or performed by the system 100 (e.g., a processor of the system 100 or any other component of the system 100).

[0047] The memory may include any type of non-transitory machine-readable medium, such as cache or system memory, including volatile and nonvolatile computer memory, such as random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), and electrically erasable PROM (EEPROM).

[0048] The processor 102 of the system 100 may be configured to communicate with the memory 104 to execute the set of instructions. The set of instructions, when executed by the processor 102, may cause the processor 102 to perform the methods described herein.

[0049] Refer again Figure 1In some embodiments, system 100 may include at least one user interface 114. In some embodiments, user interface 114 may be part of a device that also includes one or more other components of system 100 (e.g., processor 102, memory 104, and / or one or more other components of system 100). In alternative embodiments, user interface 114 may be part of a device separate from the other components of system 100.

[0050] The user interface 114 can be used to provide information obtained by the method according to the embodiments of the present invention to the user of the system 100 (e.g., a medical professional, a dermatologist, a user in a home environment, or any other user of the system 100). The instruction set can cause the processor 102 to control one or more user interfaces 114 to provide information obtained by the method according to the embodiments of the present invention when executed by the processor 102. For example, according to some embodiments, the user interface 114 can be configured to present (e.g., provide, output or display) the moisture level or lipid level of the skin determined by the system 100. Alternatively or in addition, the user interface 114 can be configured to receive user input. In other words, the user interface 114 can allow the user of the system 100 to manually input instructions, data or information. The instruction set can cause the processor 102 to obtain user input from one or more user interfaces 114 when executed by the processor 102.

[0051] The user interface 114 may be any user interface capable of presenting (or outputting or displaying) information, data, or signals to a user of the system 100. Alternatively or in addition, the user interface 114 may be any user interface that enables a user of the system 100 to provide user input, interact with the system 100, and / or control the system 100. For example, the user interface 114 may include one or more switches, one or more buttons, a keypad, a keyboard, a mouse, a mouse wheel, a touch screen or application (e.g., on a tablet or smartphone), a display screen, a graphical user interface (GUI) or other visual presentation component, one or more speakers, one or more microphones or any other audio component, one or more lights, a component for providing tactile feedback (e.g., a vibration function), or any other user interface, or a combination of user interfaces.

[0052] It will be understood that Figure 1Only components required to illustrate this aspect of the disclosure are shown, and in actual implementation, system 100 may include additional components to the components shown. For example, system 100 may include a battery or other power source for powering system 100, or a member for connecting system 100 to a mains power source. System 100 may also include a communication interface (or circuit) for enabling system 100 (or components of system 100) to communicate with components, interfaces, memories, and / or devices that are part of system 100 or outside of system 100 (i.e., separated or away from it). Such communication interfaces can communicate wirelessly with any component, interface, memory, and device via a wired connection or via any other communication (or data transmission) mechanism. In some wireless embodiments, the communication interface can, for example, communicate using radio frequency (RF), Bluetooth, or any other wireless communication technology.

[0053] As briefly described above, the system 100 is configured to measure the conductivity between at least two electrodes 108 and determine the moisture level or lipid level of the skin based on the measured conductivity and the frequency of the electrical signal.

[0054] The signal generator 106 is configured to generate an electrical signal at a first frequency and an electrical signal at a second frequency, and the system 100 may be configured to measure moisture level when the generated electrical signal is at the first frequency and to measure lipid level when the generated electrical signal is at the second frequency.

[0055] Therefore, the frequency value used to make the determination may depend on whether the system is to determine moisture level or lipid level.As mentioned above, the inventors have experimentally observed that the conductivity of the skin depends on both the lipid and moisture content of the skin.

[0056] Figure 2 Graphs of conductivity versus (or for or as a function of) frequency are shown for breast tissue 202 (eg, tissue high in lipid content), moist skin 204, and dry skin 206, respectively. Figure 2 , various conductivity ratios can be determined, which can be used to determine, with increased sensitivity, frequency ranges (e.g., frequency bands) that are most sensitive to (and therefore most suitable for measuring) moisture levels and lipid levels.

[0057] Figure 3The ratio of conductivity at different frequencies is shown. Line 302 shows the ratio of conductivity of wet skin to lipid level, line 304 shows the ratio of wet skin to dry skin, and line 306 shows the ratio of dry skin to lipid level. Four frequency ranges f1-f4 can then be defined, each frequency range being more sensitive to either moisture level or lipid level (e.g., the value of conductivity measurements made in the range is more dependent on either moisture level or lipid level). In other words, in these ranges, the contrast between lipid level and moisture level may be optimal for measuring a particular one of the moisture level and lipid level. Figure 4 Exemplary frequency ranges suitable for measuring moisture levels and lipid levels of the skin are summarized in the table shown.

[0058] Thus, the frequency of the electrical signal generated by the signal generator 106 determines whether the measured conductivity is indicative of the moisture level or lipid level of the skin.

[0059] The signal generator 106 is configured to generate an electrical signal of a first frequency in a first frequency range, and the system 100 can be configured to determine the moisture level of the skin based on the measured conductivity when the frequency of the signal is the first frequency. The first frequency range may include frequencies where the contrast between the conductivity of wet skin and dry skin is high enough to make the measured skin conductivity sensitive to the moisture level (or amount of moisture). The first frequency range may include frequencies where the contrast between lipids and the conductivity of wet skin or dry skin is low to make the skin conductivity less sensitive to the lipid level (or amount of lipid). Thus, in some embodiments, when the frequency of the signal is the first frequency, water has a greater effect on conductivity than lipids. In this way, the value of the conductivity at the first frequency depends more on (e.g., more highly on) the moisture content of the skin, and therefore, the conductivity at the first frequency (or in the first frequency range) can be used to measure moisture content more accurately than at other frequencies (or frequency ranges).

[0060] In some embodiments, the first frequency range can be a frequency range from 10kHz to 100kHz, for example, a frequency range from 20kHz to 90kHz, for example, a frequency range from 30kHz to 80kHz, for example, a frequency range from 40kHz to 70kHz, for example, a frequency range from 50kHz to 60kHz. In some embodiments, for example, the first frequency can be a frequency selected from 10kHz, 20kHz, 30kHz, 40kHz, 50kHz, 60kHz, 70kHz, 80kHz and 90kHz. In other embodiments, the first frequency range can be a frequency range from 0.8MHz to 5MHz, for example, a frequency range from 1.4MHz to 4.4MHz, for example, a frequency range from 2MHz to 3.8MHz, for example, a frequency range from 2.6MHz to 3.2MHz. In some embodiments, for example, the first frequency can be a frequency selected from 1MHz, 2MHz, 3MHz, 4MHz and 5MHz. In other embodiments, the first frequency range may be a frequency range from 500 kHz to 1 MHz, for example, a frequency range from 500 kHz to 0.9 MHz, for example, a frequency range from 500 kHz to 0.8 MHz.

[0061] Typically, the measured conductivity can be used to determine the moisture level of the skin using a relationship between conductivity and moisture level (e.g., water content) when the frequency of the electrical signal generated by the signal generator 106 is a first frequency. In some embodiments, such a relationship between conductivity and moisture level may include an empirical relationship. Typically, a calibration curve or table can be used to convert the conductivity measured by the signal generator 106 into a moisture level. Such empirical relationships, calibration curves, and / or tables can be derived by comparing the measured skin conductivity with the moisture level. For example, by comparing the measured conductivity level with the moisture level measured using a confocal Raman microspectrophotometer. In some embodiments, the empirical relationship, calibration curve, and / or table may be stored in the memory 104 of the system 100.

[0062] The derivation of empirical relationships, calibration curves, and / or tables can be referred to as calibration steps for calibrating the systems described herein. Typically, this calibration step can be performed once for the system and need not be repeated. In some embodiments, the calibration step can be performed on a calibration sample (or phantom). The calibration sample can be, for example, an emulsion made of sebum and water. Sebum and water can be mixed in known volume fractions, for example, using an emulsifier, so as to achieve uniform mixing properties throughout the sample. In some embodiments, the system can be calibrated to other industry standards, such as a keratometer (e.g., for moisture levels) and a sebum meter (e.g., for lipid levels).

[0063] The signal generator 106 is further configured to generate an electrical signal at a second frequency within a second frequency range, and the system 100 is configured to determine the lipid level of the skin based on the measured conductivity when the frequency of the signal is the second frequency.

[0064] The second frequency range includes frequencies where the contrast between the conductivity of wet skin and dry skin is low enough to make the skin conductivity less sensitive to the moisture level (or amount of moisture). The second frequency range includes frequencies where the contrast between lipids and the conductivity of wet skin or dry skin is high to make the skin conductivity more sensitive to the lipid level (or amount of lipid). Thus, in some embodiments, when the frequency of the signal is the second frequency, lipids have a greater effect on conductivity than water. In this way, the value of the conductivity at the second frequency depends more on (e.g., more highly on) the lipid content of the skin, and therefore, the conductivity at the second frequency (or in the second frequency range) can be used to measure the lipid content more accurately than other frequencies (or frequency ranges).

[0065] In some embodiments, the second frequency range may be a frequency range from 10 Hz to 500 Hz, for example, a frequency range from 50 Hz to 500 Hz, for example, a frequency range from 100 Hz to 450 Hz, for example, a frequency range from 150 Hz to 400 Hz, for example, a frequency range from 200 Hz to 350 Hz, for example, a frequency range from 250 Hz to 300 Hz. In some embodiments, for example, the first frequency may be a frequency selected from 50 Hz, 100 Hz, 150 Hz, 200 Hz, 250 Hz, 300 Hz, 350 Hz, 400 Hz, 450 Hz, and 500 Hz. In other embodiments, the second frequency range may be a frequency range from 10 MHz to 100 MHz, for example, a frequency range from 20 MHz to 90 MHz, for example, a frequency range from 30 MHz to 80 MHz, for example, a frequency range from 40 MHz to 70 MHz, for example, a frequency range from 50 MHz to 60 MHz. In some embodiments, for example, the second frequency may be a frequency selected from 10 MHz, 20 MHz, 30 MHz, 40 MHz, 50 MHz, 60 MHz, 70 MHz, 80 MHz, 90 MHz, and 100 MHz.

[0066] Typically, the measured conductivity can be used to determine the lipid level of the skin using the relationship between conductivity and lipid level (e.g., lipid or sebum content) when the frequency of the electrical signal generated by the signal generator 106 is a second frequency. In some embodiments, such a relationship between conductivity and lipid level may include an empirical relationship. Typically, a calibration curve or table may be used to convert the conductivity measured by the signal generator 106 into a lipid level. Such empirical relationships, calibration curves, and / or tables may be derived by comparing the measured skin conductivity with the lipid level. For example, by comparing the measured conductivity level with the lipid level measured using a confocal Raman microspectrometer. In some embodiments, the empirical relationship, calibration curve, and / or table may be stored in the memory 104 of the system 100.

[0067] The derivation of empirical relationships, calibration curves, and / or tables can be referred to as calibration steps for calibrating the systems described herein. Typically, this calibration step can be performed once for the system and need not be repeated. In some embodiments, the calibration step can be performed on a calibration sample (or phantom). The calibration sample can be, for example, an emulsion made of sebum and water. Sebum and water can be mixed in known volume fractions, for example, using an emulsifier, so as to achieve uniform mixing properties throughout the sample. In some embodiments, the system can be calibrated to other industry standards, such as a keratometer (e.g., for moisture levels) and a sebum meter (e.g., for lipid levels).

[0068] The second frequency range referred to herein is different from the first frequency range (or the first frequency is different from the second frequency). In this way, the system 100 can determine the moisture level of the skin using a frequency different from the frequency used to determine the lipid level of the skin, wherein the conductivity of the skin is more highly dependent on (or more affected by) the moisture level or lipid level at the first frequency and the second frequency, respectively, thereby more accurately determining the moisture level and lipid level of the skin. For example, selecting (or selecting) Figure 4 The frequency range shown allows determination of one component (eg, lipid level or water level) with less confounding effects on the other component.

[0069] In some embodiments, the system 100 may be configured to measure conductivity at a single frequency to obtain a single conductivity measurement. In these embodiments, the single conductivity measurement may be used to determine the moisture level or lipid level of the skin. For example, when the frequency of the generated electrical signal is a first frequency, the conductivity measurement may be used to determine the moisture level of the skin, and when the frequency of the generated electrical signal is a second frequency, the conductivity measurement may be used to determine the lipid level of the skin. In other embodiments, the system 100 may be configured to measure conductivity at multiple frequencies to obtain multiple conductivity measurements. In these embodiments, multiple conductivity measurements may be used to determine the moisture level or lipid level of the skin. For example, when the frequency of the generated electrical signal is in a first frequency range, the multiple conductivity measurements obtained may be used to determine the moisture level of the skin, and when the frequency of the generated electrical signal is in a second frequency range, the multiple conductivity measurements obtained may be used to determine the lipid level of the skin.

[0070] In some embodiments where multiple conductivity measurements are obtained, the system 100 can be configured to determine the moisture level or lipid level of the skin by determining an average moisture level or lipid level of the skin from the multiple conductivity measurements. For example, each conductivity measurement in the multiple conductivity measurements can be used to determine the moisture level or lipid level of the skin (e.g., depending on whether the frequency of the generated electrical signal is in the first frequency range or in the second frequency range, as described above). An average of the determined moisture levels and / or lipid levels can then be determined.

[0071] In some embodiments, the determined lipid level can be used to correct the determined moisture level. Similarly, in some embodiments, the determined moisture level can be used to correct the determined lipid level. For example, if it is known that lipids contribute a certain percentage to the measured skin conductivity value at a particular frequency, and the lipid level is known, it can be used to determine the amount of conductivity that can be attributed to the moisture level of the skin (or vice versa).

[0072] In some embodiments, system 100 can be configured to compare the measured conductivity to one or more predefined curves that describe how skin conductivity varies with frequency, and determine the moisture level or lipid level of the skin based on the comparison of the measured conductivity and the frequency of the radio frequency signal.

[0073] Examples of predefined curves are Figure 2 shown. Figure 2 The manner in which skin conductivity varies with frequency relative to different skin characteristics (e.g., high lipid content, high moisture content, and low moisture content) is depicted. A skilled person will appreciate that Figure 2Only exemplary curves are shown, and the measured conductivity level may be compared to a series of curves (eg, curves representing different levels (eg, different combinations of levels) of water and lipids).

[0074] In some embodiments, comparing the measured conductivity (e.g., multiple conductivity levels) to one or more predefined curves may include comparing the distribution of conductivity levels to a shape associated with the predefined curves. For example, the magnitude, slope, or first or second derivative of the conductivity measurement may be determined and compared to one or more predefined curves to identify whether the conductivity measurement is consistent with the magnitude, slope, or first or second derivative of the predefined curves.

[0075] In some embodiments, the moisture level and / or lipid level of the skin can be determined based on a best fit predefined curve (e.g., a curve representing the best fit of multiple conductivity measurements). The skilled person will be familiar with ways to determine a best fit curve for multiple measurements, such as, for example, a least squares fit method. In this way, multiple conductivity measurements can be fitted to a known curve to more accurately determine the moisture level and / or lipid level of the skin.

[0076] In any of the embodiments described herein, the system 100 may be further configured to determine a skin condition based on the determined moisture level or lipid level. Figure 5 1 shows how lipid levels (e.g., oiliness) and moisture levels (e.g., hydration levels) can be used to characterize skin as one of several types. For example, dry skin 502 is associated with low lipids and low moisture, dry oily skin 504 is associated with low hydrates and high lipid levels, normal skin 506 is associated with medium levels of moisture and lipids, hydrated oily skin 508 is associated with high lipid levels and high moisture levels, and hydrated skin 510 is associated with high levels of moisture and low levels of oiliness. In some embodiments, system 100 can classify skin into categories such as Figure 5 The position on the graph (or parameter space) shown determines the skin condition.

[0077] Reference Figure 6According to some embodiments, different combinations of moisture levels and lipid levels can also be associated with different skin conditions (e.g., dermatological conditions). Skin conditions such as atopic dermatitis show a decrease in skin hydration levels, reflecting a decrease in the skin's water holding capacity, increased transepidermal water loss (TEWL), and defective barrier function. The same symptoms are observed in individuals with psoriasis 606, eczema 614, and ichthyosis vulgaris 604. However, these mentioned diseases show special skin conditions in terms of the balance between hydrates and oils. Eczema 614 causes a slight loss of moisture (a small percentage) accompanied by a significant decrease in lipids (~25%), while psoriasis 606 shows a sharp decrease in hydrate levels (~70%) and a sharp decrease in lipid levels (~40-70%). Ichthyosis vulgaris 604 shows a decrease in hydration levels (~63%), while there is no significant change in superficial skin lipid levels (~±15%). Skin health is associated with the stability of the skin barrier function, which depends on the continuity of the superficial lipid structure of the skin. Figure 6 Other skin conditions shown include seborrhea 602 , acne vulgaris 612 , contact dermatitis 608 , and drug rash (eg, allergy) 610 .

[0078] The lipid phase behavior in the stratum corneum is believed to be critical to the skin barrier function, as it has been found that superficial skin lipids act as water regulators in the stratum corneum. Therefore, by determining the moisture level and / or lipid level of the skin in this way, the system 100 is able to determine the condition of the skin, and this can be used as an indicator of overall skin health. In some embodiments, the determined skin condition can be presented (or provided, output or displayed) on a user interface.

[0079] In some embodiments, further to determining a skin condition based on moisture level or lipid level, system 100 may be further configured to determine a recommendation for skin treatment based on the determined skin condition. For example, if system 100 determines that moisture level and / or lipid level is consistent with a skin condition (e.g., eczema), system 100 may recommend (or suggest) a topical cream, ointment, or other treatment to improve the skin condition. In some embodiments, the determined recommendation may be presented (or provided, output, or displayed) on a user interface.

[0080] In some embodiments, the system 100 can be connected to a memory (e.g., a data storage device, a database, or a server). For example, the connection can be a wired connection or a wireless connection. In some of these embodiments, after the skin condition has been determined and / or the suggestion for skin treatment has been determined, the system 100 can be configured to send such a determination result to the memory. In some embodiments, the system 100 can be configured to determine the lipid level and / or moisture level of the skin at periodic intervals. In some of these embodiments, the system 100 can be configured to store the results in the memory. In this way, the system 100 can track the skin condition and / or determine the improvement or change over time. Therefore, according to some embodiments, the system 100 described herein can quantitatively measure the skin condition before and after treatment by considering the changes in skin hydration level and lipid level in different locations and under different climate changes.

[0081] System 100 can provide a non-contact portable low-cost and rapid solution with the ability to measure the lipid level and moisture level of the skin. Thus, system 100 has dual modality. In addition, the storage of the measurement data can allow monitoring and control of skin conditions over time.

[0082] Now refer to Figure 7 , a method 700 for operating a system 100 to determine the moisture level or lipid level of the skin is also provided. The system 100 is as described above. In particular, the system 100 includes at least two electrodes 108 and a signal generator 106, the at least two electrodes 108 are suitable for contacting the skin, and the signal generator 106 is configured to generate an electrical signal at a frequency across the at least two electrodes 108. At box 702, the method 700 includes measuring the conductivity between the at least two electrodes 108. At box 704, the method 700 includes determining the moisture level or lipid level of the skin based on the measured conductivity and the frequency of the electrical signal. These steps are described as being performed by the system 100, and the above details will be understood to apply equally to Figure 7 The method at box 702 and box 704 of .

[0083] Also provided is a computer program product comprising a non-transitory computer readable medium having computer readable code embodied therein, the computer readable code being configured to, when executed by a suitable computer or processor, cause the computer or processor to perform any of the methods described herein.

[0084] Therefore, it will be understood that the embodiments described herein are also applicable to computer programs suitable for putting the present invention into practice, particularly computer programs on or in a carrier. The program can be in the form of source code, target code, code intermediate source and target code, such as, in the form of partial compilation, or in any other form suitable for the implementation of the method according to an embodiment of the present invention. It should also be understood that such programs can have many different architectural designs. For example, the program code implementing the function of the method or system of the present invention can be subdivided into one or more subroutines. Many different ways of allocating functions between these subroutines will be apparent to the technician. Subroutines can be stored together in an executable file to form an independent program. Such executable files can include computer executable instructions, for example, processor instructions and / or interpreter instructions (for example, Java interpreter instructions).

[0085] Alternatively, one or more or all subroutines may be stored in at least one external library file and linked to the main program statically or dynamically, for example, at runtime. The main program contains at least one call to at least one subroutine. The subroutines may also include function calls to each other. An embodiment related to a computer program product includes computer executable instructions corresponding to each processing stage of at least one of the methods set forth herein. These instructions may be subdivided into subroutines and / or stored in one or more files that may be linked statically or dynamically. Another embodiment related to a computer program product includes computer executable instructions corresponding to each component of at least one of the systems and / or products set forth herein. These instructions may be subdivided into subroutines and / or stored in one or more files that may be linked statically or dynamically.

[0086] The carrier of a computer program may be any entity or device capable of carrying the program. For example, the carrier may include a data storage device, such as a ROM, for example, a CD ROM or a semiconductor ROM, or a magnetic recording medium, for example, a hard disk. In addition, the carrier may be a transmissible carrier, such as an electrical or optical signal, which may be transmitted via an electrical or optical cable or by radio or other means. When the program is embodied in such a signal, the carrier may be constituted by such a cable or other device or member. Alternatively, the carrier may be an integrated circuit in which the program is embedded, the integrated circuit being suitable for executing or being used in the execution of the relevant method.

[0087] Those skilled in the art, after studying the drawings, the disclosure and the appended claims, can understand and implement variations of the disclosed embodiments when practicing the principles and techniques described herein. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "one" or "an" does not exclude multiple. A single processor or other unit can implement the functions of multiple items described in the claims. The indisputable fact that certain measures are described in mutually different dependent claims does not mean that a combination of these measures cannot be used advantageously. Although computer programs can be stored or distributed on suitable media, such as optical storage media or solid-state media supplied with other hardware or as part of other hardware, they can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any figure mark in the claims should not be understood as limiting the scope.

Claims

1. A system (100) for determining moisture level and lipid level of skin, the system (100) comprising: at least two electrodes (108), the at least two electrodes being adapted to contact the skin; a signal generator (106) configured to generate an electrical signal at a frequency across the at least two electrodes (108), a conductivity measurement system (112) for measuring a plurality of conductivities at a plurality of frequencies between the at least two electrodes (108), and a processor (102) for processing an output of the conductivity measurement system (112), wherein the signal generator (106) is configured to generate an electrical signal of a first frequency in a first frequency range, and the system is configured to determine the moisture level of the skin based on the measured conductivity when the frequency of the electrical signal is the first frequency, wherein the first frequency range is a frequency range from 10 kHz to 100 kHz, or a frequency range from 0.8 MHz to 5 MHz; and wherein the signal generator (106) is configured to generate an electrical signal of a second frequency in a second frequency range, and the system (100) is configured to determine the lipid level of the skin based on the measured conductivity when the frequency of the electrical signal is the second frequency, wherein the second frequency range is a frequency range from 10 Hz to 500 Hz, or a frequency range from 10 MHz to 100 MHz; and The system (100) is configured to: When the frequency of the generated electrical signal is in the first frequency range, the measured conductivity is used to determine the moisture level of the skin, and when the frequency of the generated electrical signal is in the second frequency range, the measured conductivity is used to determine the lipid level of the skin; comparing the measured conductivity to one or more predefined curves describing how skin conductivity varies with frequency; as well as The moisture level and lipid level of the skin are determined based on a comparison of the measured conductivity and the frequency of the electrical signal.

2. The system (100) according to claim 1, wherein the first frequency is 50 kHz or 1 MHz.

3. The system (100) of claim 1, wherein the second frequency is 50 Hz or 50 MHz.

4. The system (100) according to any one of the preceding claims, wherein the system (100) is configured to measure the conductivity at multiple frequencies to obtain multiple conductivity measurements.

5. The system (100) according to claim 4, wherein the system (100) is configured to determine the moisture level and the lipid level of the skin by determining the average moisture level and the average lipid level of the skin from the plurality of conductivity measurements.

6. The system (100) according to any one of claims 1-3, wherein the system (100) is further configured to: The skin condition is determined based on the determined moisture level or lipid level.

7. The system (100) according to claim 6, wherein the system (100) is further configured to: A recommendation for skin treatment is determined based on the determined skin condition.

8. A method (700) for operating a system (100) to determine the moisture level or lipid level of skin, the system (100) comprising at least two electrodes (108) adapted to contact the skin and a signal generator (106), the signal generator (106) being configured to generate an electrical signal at a frequency across the at least two electrodes (108), a conductivity measurement system (112) for measuring the conductivity between the at least two electrodes (108); and a processor (102) for processing an output of the conductivity measurement system (112), wherein the method (700) comprises: generating an electrical signal of a first frequency in a first frequency range, wherein the first frequency range is a frequency range from 10 kHz to 100 kHz, or a frequency range from 0.8 MHz to 5 MHz; measuring electrical conductivity between the at least two electrodes (108); generating an electrical signal of a second frequency in a second frequency range, wherein the second frequency range is a frequency range from 10 Hz to 500 Hz, or a frequency range from 10 MHz to 100 MHz; and measuring (702) electrical conductivity between the at least two electrodes (108); comparing the measured conductivity to one or more predefined curves that describe how skin conductivity varies with frequency; and The moisture level and lipid level of the skin are determined (704) based on a comparison of the measured conductivity and the frequency of the electrical signal.

9. A computer program product comprising a non-transitory computer readable medium having computer readable code embodied therein, the computer readable code being configured to, when executed by a suitable computer or processor, cause the computer or processor to perform the method according to claim 8.

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