Patent Description:
The skin is the largest organ of the human body, forming a physical barrier to the environment and providing important functions including insulation, temperature regulation and protection against micro-organisms, as well as touch, heat sensitivity, and other forms of sensation. The skin also regulates the passage of water and electrolytes, and produces vitamin D.

The outermost skin layer or epidermis covers the body's surface. Most of the epidermal cells are keratinocytes, which form an environmental barrier and synthesize vitamin D. The epidermis also includes melanocytes, which produce melanin to protect against harmful UV radiation, Merkel cells, which provide sensitivity to touch, and Langerhans cells, a type of white blood cell or macrophage that is part of the immune system, acting to protect the body against infection.

The epidermis surrounds the dermis. The structure of the dermis is provided by fibroblasts, which synthesize collagen and elastin proteins to form the extracellular matrix, with collagen fibers to provide strength and toughness, and elastin threads or filaments to provide elasticity and flexibility. The fibroblasts also produce proteoglycans, viscous proteins that provide hydration and lubrication, and regulate ionic binding and molecular transport. The dermis also includes macrophages and mast cells, part of the immune system, as well as the hair follicles, sweat and oil glands, nerve cells, and blood vessels.

The epidermis and dermis make up the cutis. Subcutaneous tissue connects the cutis to the underlying muscle and fascia, and to other connective tissue including the periosteum (covering the bones). The subcutis also includes elastin and adipose (fat) cells.

As the skin ages, loss of firmness and elasticity may be associated with a decrease in the production of Type I collagen (the most abundant form), as well as a reduction in elastin, proteoglycans, and other components of the extracellular matrix. Aging skin can also exhibit thinning, coloration, and reduced immune response.

A range of personal skin care products have been provided to help reduce certain aging effects, including topical products and hand-held devices for cleansing, exfoliating and smoothing the outer skin layers. A variety of galvanic (electric current-based) treatment devices are also known, for example as described in <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>, originally assigned to Alza Corporation of Palo Alto, California; <CIT>, originally assigned to LTS-LohmanTherapie-Systeme ofNeuweid, Germany; <CIT>, originally assigned to Viteris, Inc. , of Fair Lawn, New Jersey; and <CIT> and <CIT>, originally assigned to Birch Point Medical of Oakdale, Minnesota. Other stimuli are also possible, for example in the form of light energy as described in <CIT>, originally assigned to LED Intellectual Properties of Irvine, California.

In galvanic systems, one or more anode or cathode electrodes are arranged to produce an electric potential across the skin, providing current flow through the epidermal and dermal layers. Advanced microcurrent based devices can include a control circuit operably connected to the electrodes, in order to carefully regulate the current to promote ion transport and other biological effects; e.g., as described in <CIT> and <CIT> and <CIT>, to NSE Products of Provo, Utah.

More generally, the skin's response to electric current flow involves a number of complex and interacting biological processes, and the full range of different treatment mechanisms have not all been recognized in the prior art. As a result, there is an ongoing need more progressive approaches to skin care, including microcurrent based skin treatment techniques developed with a better understanding of the underlying biological responses, and modulated electrical waveforms and energetic stimuli providing for improvements in treatment response and user comfort.

<CIT> discloses apparatuses and methods of applying transdermal electrical stimulation (TES) to a subject to enhance a concurrent sensory experience, by applying the TES to the subject's head or head and neck from two or more electrodes that are coupled to a neurostimulator. The apparatuses and methods described are configured to apply an ensemble current waveform between the two or more electrodes, wherein the ensemble current waveform comprises a series of component waveforms that are sequentially applied, and wherein each component waveform is different from a component waveform immediately before it and wherein transitions between the component waveforms temporally correlates with transitions in the sensory experience. Also described are apparatuses and methods for applying TES to a subject's face or face and neck, wherein one end of the TES applicator (e.g., strip electrode) contacts the subject's cheek and/or mastoid.

<CIT> discloses systems and methods for enhancing or affecting neural stimulation efficiency and/or efficacy. A system and/or method may apply electromagnetic stimulation to a patient's nervous system over a first time domain according to a first set of stimulation parameters, and over a second time domain according to a second set of stimulation parameters. The first and second time domains may be sequential, simultaneous, or nested. Stimulation parameters may vary in accordance with one or more types of duty cycle, amplitude, pulse repetition frequency, pulse width, spatiotemporal, and/or polarity variations. Stimulation may be applied at subthreshold, threshold, and/or suprathreshold levels in one or more periodic, aperiodic (e.g., chaotic), and/or pseudo-random manners. Stimulation may comprise a burst pattern having an interburst frequency corresponding to an intrinsic brainwave frequency, and regular and/or varying intraburst stimulation parameters. Stimulation signals providing reduced power consumption with at least adequate symptomatic relief may be applied prior to moderate or significant power source depletion.

<CIT> discloses a computer-implemented method of providing a cranial electrotherapy stimulation program for use in a stimulation system comprising generating a chaotic cranial electrotherapy stimulation program.

<CIT> discloses an electrostimulation device and method of systematically compounded modulation of current intensity with other output parameters for affecting biological tissues. <CIT> discloses electro-stimulation of systematically compounded modulation of current intensity with other output parameters for affecting biological materials. <CIT> discloses systems and methods for applying electrical energy to treat psoriasis.

The invention is defined in independent claim <NUM> and independent claim <NUM>. Aspects, embodiments and examples of the present disclosure which do not fall under the scope of the appended claims do not form part of the invention and are merely provided for illustrative purposes.

Although the present disclosure describes particular examples and preferred embodiments of the invention, persons skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the claims. The various examples and embodiments are also described with reference to the drawings, where like reference numerals represent similar structural and functional components throughout the several views. These examples and embodiments do not limit practice of the invention as claimed; rather, the specification merely sets forth representative applications to different systems, methods and devices, and practice of the invention is not limited except as set forth in the appended claims.

Modulated waveforms can be used to define a range of energetic stimuli adapted for skin care and treatment, including galvanic and microcurrent-based treatments, and for other voltage or current-based devices. Waveform modulation can also be used to generate an LED, laser, or other electromagnetic stimulus, in radio frequency (RF), infrared (IR), near-ultraviolet (near-UV) or ultraviolet (UV) frequency range, or an ionizing radiation treatment, for cosmetic, non-cosmetic, medical or non-medical applications, consistent with all applicable legal and regulatory requirements. Acoustic stimuli can also be produced, for example in the subsonic, sonic, or ultrasonic ranges, or a combination of voltage, current, electromagnetic, and acoustic stimuli can be applied.

While various relationships between the modulated signal amplitude, treatment time and efficacy have been explored in certain prior art, there are still substantial design challenges in this area. In particular, there are no definitive modulation parameters that can be uniformly applied to improve the results of a particular skin treatment, across the full range of different potential applied stimuli. Nor have more generalized signal modulation techniques been identified to improve treatment efficacy, while reducing user discomfort and avoiding the possible tendency for homeostasis, which may substantially impact treatment benefits over time.

A randomized or pseudorandomized approach to waveform modulation is employed to address some or all of these issues. In this approach, a set of pulses in the waveform can be modulated or controlled to vary by pulse width, period, frequency, or amplitude, in a random, pseudorandom, or aperiodic manner. The modulation can include both pseudorandom variations based on computational algorithms, or "true" random variations based on probabilistic physical phenomena, such as atmospheric or thermal noise, background fluctuations, radioactive decay, or other quantum phenomena, and adapted to provide statistically random sequence of pulse variations, as described in the present specification, and as known in the art.

Randomized waveform modulation can be defined locally, over a given set of pulses within a treatment cycle or phase, or more globally, over a number of such phases making up a treatment cycle. Quantum-computer based randomization can also be used to generate the random pulse variation, or, more generally, a combination of random, pseudorandom, and quantum-based effects, selected to provide statistically randomized pulse parameters; for example, in either a non-repeating or aperiodic sequence, or without other recognizable patterns or regularity, i.e., any form of randomization that leads to a waveform that when analyzed over a relevant time period can be found to have some amount of statistical randomness as known in the field, in at least some aspect of the waveform. The random or pseudorandom sequence can be determined in real time, or predefined (e.g., using a random or pseudorandom generator to determine one or more such sequences), and then re-ordered for application to the subset of consecutive pulses defining each phase, or to the full set of consecutive pulses defining the a treatment cycle.

This randomized approach to waveform modulation can provide substantial improvements in skin health and appearance, while improving user comfort and potentially reducing the possible tendency for homeostasis; that is, the tendency to adjust to relatively stable equilibrium, in response to an applied stimulus. These improvements can be defined over a wide range of treatment criteria, using both quantitative user evaluations, a highly relevant measure for personal skin care and treatment technologies, and based on definitive clinical trial data, using on objective, blinded, clinical grader results, independent of the user evaluations, as described in detail below.

<FIG> is a sectional diagram illustrating representative structural and functional components of human skin <NUM>. As shown in <FIG>, the skin (or "cutis") <NUM> includes an upper epidermal layer (or epidermis) <NUM> extending from the skin surface <NUM> to a lower dermal layer (dermis) <NUM>. Together, the epidermis <NUM> and dermis <NUM> make up the cutaneous tissue or skin. The subcutaneous tissues comprise the subcutis (or hypodermis) <NUM>, underlying the cutis <NUM>.

Collagen fibers <NUM> extend from the lower dermis <NUM> through the subcutis <NUM>, forming bands and sheets of connective tissue (fascia) connecting the skin (cutis) <NUM> to the underlying muscles and connective tissue. The dermis <NUM> also includes a papillary layer <NUM> and a reticular layer <NUM>, formed of more loosely arranged and denser collagen fibers, respectively.

The subcutis <NUM> includes adipose tissues <NUM>, for example in the form of lipocytes (fat cells) and intracellular or intercellular lipids, which can form lobules <NUM> and other structures between the collagen fibers <NUM>. A network of small blood vessels or capillaries <NUM> provide circulation, extending from the subcutis <NUM> into the dermis <NUM>.

<FIG> is a sectional diagram illustrating an electrical stimulus <NUM> propagating through different layers of the skin or cutis <NUM>. For example, in one embodiment a current or microcurrent stimulus <NUM> can be generated by one or more electrodes or emitters <NUM> disposed along the skin surface <NUM>. A gel or other topical skin treatment product <NUM> can be applied to the skin surface <NUM> to improve conductivity, and to provide the skin <NUM> with nutrients and other beneficial agents. It is also possible to use electromagnetic energy as a form of stimulus <NUM> to treat skin, for example in the form of radio frequency (RF), infrared (IR), optical or ultraviolet (UV) light (e.g., low-energy near UV light), or to provide an energetic stimulus <NUM> in the form of sonic, subsonic or ultrasonic acoustic energy. These energetic stimuli can be presented to the skin as a modulated waveform, similar to the modulated waveforms provided in the form of an electrical or current stimulus <NUM>. Thus, electrical, electromagnetic and acoustic forms of energy are all within the teachings of the present disclosure, and any suitable combination of these energetic stimuli can be presented in the form of a modulated waveform.

As shown in <FIG>, for example, an electrical stimulus <NUM> can be generated by applying a potential V (or current source I) between two or more electrodes or emitters <NUM>, spaced along the outer surface <NUM> of the skin <NUM>, either adjacent to or in direct contact with the skin surface <NUM>. Alternatively, one or more electrodes <NUM> may be disposed on or adjacent the skin surface <NUM> in a particular location, for example on the face, arm, torso or leg, with another electrode <NUM> coupled remotely, for example via contact with the hand of the user (or other treatment subject), or elsewhere on the subject's body. In other applications, the electrical stimulus <NUM> can be applied with a single electrode <NUM>; e.g., by applying an ungrounded (floating) potential waveform from one or more electrodes <NUM> to the skin surface <NUM>, or by forming a current loop through the subject's feet or other ground contact.

Depending upon application, a potential V can be provided to the electrodes or emitters <NUM> to apply a current stimulus <NUM> to the top epidermal layer <NUM> of the skin <NUM>, or a current propagating through the epidermal layer <NUM> to one or both of the (upper) papillary layer <NUM> and (lower) reticular layer <NUM> of the dermis <NUM>. The electrical stimulus may also propagates into or through the subcutis <NUM>, promoting a favorable response from both cutaneous and subcutaneous tissues. The stimulus <NUM> can thus promote a range of biological responses in epidermal, dermal (cutaneous) and subcutaneous tissues. Alternatively one or more (or all) of the electrodes or emitters <NUM> can take the form of LEDs or laser light sources (or other electromagnetic emitters) configured to provide a stimulus in the form of RF, IR, optical or UV light energy, or one or more acoustic transducers configured to provide a subsonic, sonic, ultrasonic, or other acoustic stimulus, or any suitable combination of electrical, acoustic, and electromagnetic emitters <NUM>.

In particular examples, a DC (direct current) or pulsed DC potential V or current I is applied via the electrodes <NUM>, so that the electrical stimulus <NUM> propagates in a particular direction through the skin <NUM>. In other examples, an AC (alternating current) potential V of current I can be applied, so that the electrical stimulus <NUM> propagates back and forth, in alternating fashion.

The potential V can be applied as a steady-state (constant or alternating) voltage signal, or using a modulated waveform. Depending on application, the pulse width, amplitude, period and frequency of the applied voltage V or current I can all be controlled, either individually or in combination, in order to generate the electrical stimulus <NUM> as an AC, DC or pulsed DC current treatment for the skin <NUM> of the user or other subject. In particular applications, pulse with modulation (PWM) can be used to generate the stimulus <NUM> as a pulsed microcurrent signal, or other energetic stimulus <NUM>, for example by applying a programmed, random or pseudorandom pulse width modulated (PRPWM) current or voltage waveform, or as a modulated electromagnetic or acoustic waveform, as described herein.

<FIG> is a block diagram of a representative device or apparatus <NUM> configured for microcurrent based skin treatment, or other energetic stimulus <NUM> according to <FIG>. As shown in <FIG>, microcurrent device <NUM> includes a housing <NUM> with a power supply (P/S) <NUM>, a current or voltage generator (V/I) <NUM> electrically connected to one or more electrodes or other emitters <NUM>, a microprocessor (µP) based controller <NUM>, memory <NUM> and an external communications interface <NUM>.

Power supply <NUM> can be provided in the form of a rechargeable capacitor or battery system, for example with a power port <NUM> adapted for external wired or wireless (e.g., inductive) charging. The microprocessor controller <NUM> is provided in data communication with the memory <NUM>, which provides storage for control code <NUM> and operational data <NUM>. The communications interface (I/F) <NUM> can be adapted for both data and control communications with the controller <NUM>, for example using a hard-wired communication port or wireless device <NUM>.

In operation of device <NUM>, power supply <NUM> provides power to the voltage or current generator (or source) <NUM>, as well as the microprocessor controller <NUM>, memory <NUM> and interface <NUM>. Controller <NUM> is configured regulate the potential (V) or current (I) signal generated by source <NUM>, for example by executing control code <NUM> stored in memory <NUM>. Control parameters and other operational data <NUM> can be used for modulating the signal provided to each selected electrode or emitter <NUM>, in order to deliver the desired amplitude, frequency, and pulse width modulation. One or more skin sensors <NUM> can also be provided, for example to measure skin surface temperature and resistivity, and to determine other skin conditions such as hydration, etc. Additional sensors <NUM> can also be provided to measure or monitor environmental conditions such as ambient temperature and humidity, etc..

The microprocessor controller <NUM> can also be adapted to monitor feedback signals from the electrodes or emitters <NUM>, and for regulating the applied potential (V) or current (I) responsive to the feedback. Feedback-based regulation allows the controller <NUM> to maintain the desired electrical stimulus <NUM>, taking into account the number and arrangement of electrodes <NUM> as well as the subject's skin type and related skin conditions such as resistivity, temperature, hydration, etc., for example as determined with additional data from one or more skin sensors and other environmental sensors <NUM>. The controller <NUM> can also be adapted to regulate the current stimulus <NUM> transmitted through the subject's skin based the voltage (V) or current (I) signal actually applied to the electrodes <NUM>, and on other operational and environmental conditions such as the presence or absence of a conductive gel or other skin treatment product between the electrodes <NUM> and the skin surface, and the record of other recent and historical treatment information recorded in the operational data <NUM>.

<FIG> is a block diagram illustrating a representative method or process <NUM> for microcurrent-based skin treatment, for example using the device <NUM> of <FIG>. As shown in the particular example of <FIG>, method <NUM> comprises one or more steps of determining operational data (step <NUM>), defining a stimulus (step <NUM>), generating a waveform (step <NUM>), modulating the waveform (step <NUM>), and applying the stimulus (step <NUM>), based on the modulated waveform.

Depending on application, method <NUM> may also include monitoring feedback (step <NUM>), and regulating the modulated waveform (step <NUM>); e.g. in order to reduce differences between the defined and applied stimuli. These steps can be performed in any order or combination, with or without additional procedures. For example, monitoring feedback (step <NUM>) can also include monitoring sensor data, for example to determine skin conditions (step <NUM>) and environmental conditions (step <NUM>).

Determining operational data (step <NUM>) can be performed as an initiation or start operation for method <NUM>, for example by reading the operational data from memory. The operational data can include a set of operational parameters for performing the steps of method <NUM>, or data used to generate such a parameter set. For example, the operational data may include stimulus data or parameters from which a desired stimulus can be selected or defined (step <NUM>), and waveform data or parameters from which a desired voltage or current waveform can be generated (step <NUM>).

The waveform data can also include a set of selected pulse parameters for modulating the waveform (step <NUM>), so that the desired stimulus can be delivered or applied to the skin of a subject (step <NUM>). The pulse parameters can be selected to characterize one or more pulse widths for "on" and "off" portions of the cycle, as well as pulse periods, frequencies and amplitudes.

The applied waveform may be either unipolar or bipolar; for example as defined based on the sign of the amplitude parameter, or by defining an absolute (non-negative) amplitude with a separate polarity parameter to determine the sign. The pulse modulation can be randomized by assigning selected parameters to consecutive pulses in a random or pseudorandom sequence, or by including a random or pseudorandom component in the modulated pulse parameters themselves, in order to generate a non-repeating or aperiodic sequence of modulated pulses.

For example, the pulse width, period, frequency, amplitude or other modulated pulse parameter may be aperiodic or non-repeating over a given set of pulses, so that the modulated parameter does not repeat at all, or does not repeat with any identifiable pattern or sequence, within the given subset or set. The aperiodic or non-repeating pulse parameter can be modulated over a set of consecutive pulses defining a treatment cycle with one or more treatment phases, or over a subset of consecutive pulses defining one or more of the phases.

The applied stimulus (step <NUM>) can be monitored (step <NUM>) by measuring the applied voltage or current flow through the electrodes or other emitters. Feedback parameters can be used to regulate the modulated waveform (step <NUM>), for example by applying a hardware or software-based gain parameter to reduce any difference between the stimulus that is defined (at step <NUM>), and the stimulus that is actually applied (at step <NUM>). Feedback monitoring (step <NUM>) can also include receiving sensor data used to determine skin and environmental conditions such as resistivity, surface temperature, hydration, ambient temperature, humidity, etc. (steps <NUM> and <NUM>).

The operational data (step <NUM>) can also include historical log data for prior operation of a suitable microcurrent device <NUM> according to method <NUM>. For example, the log data can be recorded to characterize previously defined stimuli (step <NUM>), and to record the parameters used for waveform generation (step <NUM>) and modulation (step <NUM>). Additional log data can provide records of stimuli that were actually delivered or applied in previous treatments (at step <NUM>), as well as the electrode or emitter and sensor feedback (step <NUM>), and additional parameters used to regulate the modulated waveform (step <NUM>), to determine resistivity and other skin conditions (step <NUM>), and to describe relevant environmental conditions (step <NUM>).

Waveform modulation (step <NUM>) can apply a variety of different pulse modification techniques. In the radio-frequency (RF) range, for example, amplitude modulation (AM) and frequency modulation (FM) are commonly used. In these techniques, the modulated waveform is typically a sinusoidal carrier wave generated at a particular carrier frequency, for example in the kilohertz (kHz), megahertz (MHz), or gigahertz (GHz) range.

In amplitude modulation (AM), the amplitude of the carrier wave can be varied according to an analog (e.g., audio-frequency) signal. The modulated carrier signal is demodulated at the receiver, separating the information-carrying modulation frequencies from the carrier wave. For analog modulations in the audio-frequency range of about <NUM>-<NUM>, typical carrier frequencies extend from the tens of kilohertz (kHz) into the tens of megahertz (MHz) and above.

In frequency modulated (FM) techniques, the instantaneous frequency of the carrier wave is varied, rather than the amplitude. For audio-range applications, FM carrier frequencies traditionally extend from about ten megahertz (<NUM>) and above into the gigahertz (GHz) range. Frequency shift keying (FSK) can also be applied across a range of both lower and higher frequencies, for example to encode digital signals by shifting the carrier frequency among a selected set of discrete adjacent frequencies.

In skin treatment applications, the stimulus is not limited to a narrow-band carrier wave, by can also be defined (step <NUM>) in terms of a pulsed waveform (step <NUM>), to which programmed, randomized pulsed waveform modulation (PRPWM) can be applied (at step <NUM>) in order to deliver the desired stimulus (step <NUM>) to the subject's skin. Programmed, randomized pulsed waveform modulation can also be adapted to ensure charge and power balancing, and to incorporate a more advanced understanding of the body's underlying biological mechanisms, including the effects of randomized pulse width modulation on the body's homeostatic response.

<FIG> is a block diagram of a method or process <NUM> for pulsed waveform modulation. For example, method <NUM> may be used to operate a device <NUM> having one or more electrodes or emitters <NUM>, as shown in <FIG>, and adapted to apply a pulse modulated electrical stimulus <NUM> to a subject's skin, as shown in <FIG>. Similarly, method <NUM> can also be adapted to modulate a waveform for microcurrent-based skin treatment, for example according to method <NUM> as shown in <FIG>.

As shown in <FIG>, method <NUM> includes generating a pulsed waveform (step <NUM>), modulating the waveform (step <NUM>), and applying a pulse modulated stimulus (step <NUM>). These steps can be performed in any order or combination, with or without additional processes. For example, method <NUM> may also include monitoring a combination of sensor and electrical feedback (step <NUM>), and regulating the modulated waveform (step <NUM>) based on the feedback; e.g., in order to match the predefined and applied stimuli according to steps <NUM> and <NUM>-<NUM> of method <NUM>.

Generating a pulsed waveform (step <NUM>) comprises providing a pulsed electrical signal, for example using a voltage or current generator <NUM> as shown in <FIG>. The pulsed waveform can be sinusoidal or non-sinusoidal, for example a square wave, rectangular wave, saw-tooth, or triangular waveform, or other periodic or aperiodic function. The waveform can also be generated with either positive or negative polarity, or in bipolar form, and may be referenced to ground or superposed on a DC signal with either positive or negative bias.

Pulsed waveform modulation (step <NUM>) encompasses a range of modulation techniques including pulse width modulation (PWM; step <NUM>), pulse frequency modulation (PFM; step <NUM>), pulse amplitude modulation (PAM; step <NUM>), and combinations thereof. In particular examples, random or pseudorandom pulse width modulation (RPW) <NUM> can be applied to enhance biological response when the stimulus is applied to a subject's skin, (step <NUM>), and to reduce the tendency for homeostasis.

Pulse width modulation (PWM; step <NUM>) is a technique for selectively distributing power over the individual pulses in a pulsed waveform or carrier wave, according to a desired (e.g., analog or digital) modulation function. The average value of the power delivered is determined according to the time integral of the modulated voltage and current waveforms, while the instantaneous power is determined by the respective amplitudes at a particular time. Since the pulse width is also reflected in the length or duration of the signal, pulse width modulation can also be described as pulse duration modulation (PDM).

In pulse frequency modulation (PFM) <NUM>, the frequency of the pulsed waveform can be varied either independently of the pulse width and amplitude, or in combination. Variations in the frequency are reflected by changes the period between consecutive pulses, and can be performed according to either an analog or digital modulation signal, for example by frequency-shift keying (FSK), in which the pulse-to-pulse frequency is varied among a selected set of discrete digital frequency changes.

In pulse amplitude modulation (PAM) <NUM>, the amplitude of the pulsed waveform (or carrier wave) can be varied from pulse to pulse, either independently of or in combination with one or more the pulse width, pulse period and carrier frequency. Pulse amplitude modulation (PAM) can also be applied as an analog or digital modulation technique, for example by amplitude-shift keying (ASK), in which the pulses are modulated according to a selected set of discrete amplitudes, each assigned to a different digital value.

In randomized pulse width modulation (RPW; step <NUM>), the widths of individual waveform pulses are modulated according to a randomized or pseudo-random scheme. The pulse width and duty cycle of the waveform can be randomized independently of the pulse frequency and amplitude, or the techniques can be combined, as described below.

The modulated waveform can be applied (step <NUM>) in the form of an electrical voltage or current, for example as delivered to a subject's skin by one or more electrodes or emitters <NUM>, as shown in <FIG>. Feedback from the electrodes <NUM> and one or more sensors <NUM> can also be monitored (step <NUM>), in order to determine differences between the defined stimulus and the stimulus that is actually applied.

The modulated pulse width can be regulated (step <NUM>) according the feedback, in order to match the applied stimulus to the desired effect. For example, the amplitude of a given voltage stimulus can be regulated according to the skin's resistivity, in order to deliver a desired current stimulus. Alternatively, any combination of the pulse width, frequency and amplitude of the applied stimulus can be regulated according temperature, hydration level, and other skin and environmental conditions, or based on the presence or absence of a topical treatment between the treatment electrodes (or other emitters) and the skin surface.

Randomized pulse width modulation (RPW) <NUM> can also encompass any combination of pulse width modulation (PWM) <NUM>, pulse frequency modulation (PFM) <NUM>, and pulse amplitude modulation (PAM) <NUM>, as described above. For example, a set of individual "on" and "off" pulse widths can be defined within a particular range, and then randomly sequenced for application to consecutive pulses in the waveform, using a machine-based pseudorandom number generator (PRNG), or a hardware-based ("true") random number generator (HRNG).

Alternatively, the pulse widths can be defined with a randomized or pseudorandom component, and applied sequentially to the consecutive pulses, with or without an additional sequential randomization step. Similar randomization techniques can also be used to modulate of the pulse amplitude, pulse period and frequency, producing a modulated waveform with any suitable combination of constant, deterministic and random or pseudorandom pulse amplitude, frequency and width.

If the total pulse period ("on" plus "off") period is fixed, for example, the pulse width can nominally be modulated independently of the instantaneous (pulse-to-pulse) carrier frequency, although the changing pulse width will still be reflected in the Fourier transform. If the total period ("on" plus "off") is not fixed, both the pulse width and the instantaneous carrier frequency will change from pulse to pulse. Similarly, while the pulse amplitude can nominally be modulated independently of the pulse width and instantaneous carrier frequency (based on the pulse-to-pulse period), the frequency of any amplitude modulation will be reflected as sidebands in the Fourier transform. All of these randomized modulations of the applied stimulus can enhance the skin's response, and provide additional benefits for skin treatment, as described according to the various examples herein.

<FIG> is an amplitude-time plot of a pulse width modulated (PWM) waveform <NUM>, with randomized pulse width modulation (RPW) modulation. The vertical axis represents the pulse amplitude, in arbitrary units. The horizontal axis represents time, also in arbitrary units.

In the particular example of <FIG>, programmed randomized pulse width modulation (PRPWM) is used. Waveform <NUM> is generated as a series of individual pulses <NUM> with modulated "on" pulse width W= Wi, Wj, etc., and corresponding "off" pulse segments <NUM> with width W' = Wi', Wj', etc. The nominal pulse amplitude is substantially constant at A = A0. The instantaneous carrier frequency f = <NUM>/T varies from pulse to pulse according to the total (on + off) period T; that is, with Ti = Wi + Wi', Tj = Wj + Wj', etc..

The pulses <NUM> in waveform <NUM> can be generated in unipolar or bipolar form. For example, waveform <NUM> may define a treatment cycle that includes one or more alternating trains or phases <NUM> and <NUM> of consecutive positive or negative polarity pulses <NUM>, with individual pulses <NUM> separated by "off' segments <NUM> as shown in <FIG>. In this particular example, pulses <NUM> have positive amplitude +A0 > <NUM> in the first (positive) phase <NUM>, and negative amplitude -A0 < <NUM> in the second (negative) phase <NUM>.

In unipolar applications, waveform <NUM> can define a treatment cycle that includes a number of positive pulses <NUM> (amplitude +A0 > <NUM>) arranged in one or more positive phases <NUM>, or a number of negative pulses <NUM> (amplitude -A0 < <NUM>) arranged in one or more negative phases <NUM>. The pulse number and amplitude may vary from phase to phase, and polarity of the phases <NUM> and <NUM> can be reversed, without loss of generality. Pulses <NUM> can also be generated in bipolar form; e.g., with a positive pulse segment transitioning to a negative pulse segment, or vice-versa, and a bias can be applied to the baseline amplitude, with pulse amplitudes ±A0 measured from the bias value.

In the particular example of <FIG>, both the "on" pulse widths W = Wi, Wj and the "off" segment widths Wi', Wj' vary with respect to the nominal width WO, according to a random or pseudorandom modulation function. The first phase <NUM> may have the same number (N) of pulses <NUM> as the second phase <NUM>, or a different number, and the sequences of pulse widths Wi, Wi', Wj, Wj' may be the same or different. For example, the same set of randomized pulse widths Wi, Wi', Wj, Wj' can be used for both phases <NUM>, <NUM>, in the same order, so that the pulse trains are the same except for polarity, with periods Ti, Tj and on/off pulse widths Wi, Wi'; Wj, Wj' being the same for each sequences of pulses <NUM> in both positive phase <NUM> and negative phase <NUM>, in the same order. Alternatively, the sequence of pulses widths can be randomized, or the sequence can shifted or reversed, or otherwise change from phase to phase, so that Ti, Tj and on/off pulse widths Wi, Wi'; Wj, Wj' vary from pulse to pulse <NUM> in each phase <NUM>, <NUM>, in any order.

The power delivered by waveform <NUM> depends upon the pulse frequency (f = <NUM>/T0), the pulse height or amplitude (A), and the duty cycle, which is determined by the widths of the on and off segments of each individual pulse <NUM> (Wi, Wi', Wj, Wj', etc.). In current-based applications, the power can be expressed a product of the current and voltage P = I×V, where the pulse amplitude typically represents either the voltage (V) or the current (I), or the power itself (P). More generally, skin tissue may have a complex impedance reflecting a combination of resistive and reactive (capacitive and inductive) effects, and the power function will account for both the frequency and phase of the current and voltage signals.

The duty cycle of the modulated waveform <NUM> is determined by the "on" pulse width Wi, Wj, as compared to the respective period Ti, Tj, over the total treatment time in each phase <NUM>, <NUM>. In square wave pulses, for example, the widths of the on and off pulse segments are equal, and the duty cycle is <NUM>%. For randomized pulse with modulation, as described here, the duty cycle can vary from pulse to pulse and from phase to phase, or the duty cycle can be constrained be to have a particular value based on the integrated pulse width for each phase, for example around <NUM>%, or anywhere from a few percent or less (≤ <NUM>-<NUM>%), up to ninety percent or more (≥ <NUM>%). Similar techniques can also be applied to modulate the pulse period (T) and amplitude (A) in order to main maintain charge balance.

In particular applications, each phase <NUM>, <NUM> may include from one to ten or more individual pulses <NUM> (N), delivering a current (I) of up to <NUM>-<NUM> microampere (µA), or more. The individual "on" and "off" pulse widths (Wi, Wi', Wj, Wj') can vary from a few milliseconds or less (T ≤ <NUM>-<NUM>), up to a few tenths of a second or more (T ≥ <NUM> - <NUM>).

Since the pulse widths are randomized, the power function also varies from pulse to pulse, and the variations may be aperiodic (or non-repeating) both within a particular phase, and over consecutive phases <NUM>, <NUM>. For example, the pulse widths can be modulated within a selected range of the nominal width WO; e.g., from about <NUM> × WO or <NUM> × WO to about <NUM> × WO, or from about <NUM> × WO to about <NUM> × WO, or from about <NUM>× WO (or less) to about <NUM> × WO (or more).

More generally, the pulse width, period, frequency, or amplitude (or other modulated pulse parameter) may vary over a similar range, as compared to the average or nominal value of the modulated parameter. The average of nominal values can be defined or determined across a subset of consecutive pulses defining a phase of a selected treatment cycle, or across the set of consecutive pulses defining the treatment cycle itself. The variation in the modulated pulse parameter can be <NUM>% or less of the nominal or average value, or at least <NUM>% of the average or nominal value. The variation in the modulated pulse parameter can be at least <NUM>% or at least <NUM>% of the nominal or average value, for example up to <NUM>% of the nominal or average value, up to <NUM>% of the nominal or average value, or up to two times the nominal or average value. The variation in the modulated pulse parameter can also extend up to ten times the nominal or average value, or up to one hundred times the nominal or average value, or more.

The variation can be aperiodic non-repeating fashion over a given set or subset of pulses, so that the modulated parameter does not repeat at all, or does not repeat with any identifiable pattern or sequence, within the given subset or set. Sets or subsets of consecutive pulses <NUM>, can be defined over a treatment cycle comprising one or more treatment phases <NUM>, <NUM>, or over one or more phases <NUM>, <NUM> within a treatment cycle. For example, the pulse widths (or other pulse parameters) can be assigned to consecutive pulses <NUM> in each of the phases <NUM> or <NUM> using a random, pseudorandom, or predefined sequence, such that the pulse parameters are aperiodic or non-repeating within each individual phase <NUM>, <NUM>, or across one or more phases <NUM>, <NUM> that make up a treatment cycle.

Alternatively, the pulse parameters can be non-repeating or aperiodic as defined globally, over the complete set of pulses <NUM> defining a treatment cycle including any number of individual phases <NUM>, <NUM>. For example, a suitable random or pseudorandom sequence can be defined in real time, and assigned to consecutive pulses <NUM> in one or more phases <NUM>, <NUM>, or a suitable sequence can be predefined using a random or pseudorandom pattern, and then rearranged or reordered for each phase <NUM>, <NUM>. Individual pulses <NUM> can also be assigned random or pseudorandom components, or using a predefined random or pseudorandom sequence or pattern, so that the modulated parameters are non-repeating or aperiodic over the individual pulses in each phase <NUM>, <NUM>, or over a treatment cycle including any number of such phases.

The treatment time varies depending on the pulse frequency (f) and period (T), as well as the number of individual pulses <NUM> in each phase <NUM>, <NUM>. In some applications, for example, ten or more (N ≥ <NUM>) pulses <NUM> can be sequentially distributed over each phase <NUM>, <NUM> with an average pulse period of about <NUM>, and delivered over a time period of about <NUM> (<NUM>). Alternatively, the number of pulses per phase may vary from one to about <NUM> or more. The average pulse period may vary from about <NUM> or less to about <NUM> or more, corresponding to treatment times ranging from a second or less up to ten seconds or more.

The total treatment cycle time depends on the average pulse period, the number of pulses per phase, and the number of phases that are applied. A typical treatment cycle may include up to ten phases or more of each desired polarity, with a total treatment cycle time ranging from up to ten seconds or more (e.g., ≥ <NUM>). In other applications the number of phases varies, for example from one to ten or more, or from ten to fifty or more, or from fifty to one hundred or more, and the total treatment cycle time can range from about a few seconds or less (≤ <NUM>-<NUM>) to a few minutes or more (>_ <NUM>-<NUM>).

The randomized modulating function can be constrained or controlled so that the absolute value of the integrated pulse height is the same in each successive phase <NUM> or <NUM>, in order to achieve charge balance. When delivering electrical stimuli such as microcurrent skin treatments, for example, the integrated current or charge applied in each positive-polarity phase <NUM> can be constrained to equal the absolute value of the integrated current or charge delivered in each negative polarity phase <NUM>, so that the net current and charge delivered to the skin are balanced.

In charge balanced applications, the integrated power delivered in successive phases <NUM>, <NUM> is substantially the same, and the net integrated charge and current are at, near, or approaching zero (that is, within a selected limit or minimum threshold value of zero). Alternatively, the modulation function may be unconstrained with respect to one or more parameters (e.g., pulse width, period, frequency, or amplitude), and the integrated charge or current may vary not only from pulse to pulse, but also from phase to phase.

<FIG> is an amplitude time plot of a randomized pulse width modulated (RPW) waveform <NUM>, with substantially constant pulse period T0 and carrier frequency f = <NUM>/T0. The vertical axis represents the pulse amplitude and horizontal axis represents time, with both axes scaled in arbitrary units.

As shown in <FIG>, waveform <NUM> is generated as a series of individual pulses <NUM> with fixed or nominal amplitude A = A0, distributed over a number of phases <NUM>, <NUM> having opposite polarity. The individual pulses <NUM> have variable ("on") pulse width W = Wi, Wj, etc., separated by variable-width "off" pulse segments <NUM>, for which the amplitude is either substantially zero, or fixed at a selected bias value. In this particular example, some pulses <NUM> have a larger than nominal width Wi > W0, corresponding to a positive pulse width deviation Δi(+) = +|Wi - W0|, and others pulses have a relatively smaller width Wj < W0, corresponding to a negative deviation Δj(-) = -|W0-Wj|.

The individual deviations in period Δi, Δj may also vary among the different phases <NUM>, <NUM>, as shown in <FIG>. Each of the pulse widths Wi, Wj can thus be different, so that the modulated waveform <NUM> is non-repeating and aperiodic over each treatment phase <NUM>, <NUM>, or over an entire treatment cycle including any number of phases <NUM>, <NUM>. Alternatively, the values of the individual pulse widths W = Wi, Wj, can be randomly sequenced within each phase <NUM>, <NUM>, or across the treatment cycle, or in another suitable non-repeating or aperiodic fashion.

The modulation function in <FIG> is constrained so that adjacent pulses <NUM> remain distinct in time; for example, with positive deviation limited by |Δi| < |T-WO|, and negative deviation limited by |Δj| < |WO|. The modulation function can also be constrained to maintain a selected average duty cycle over each treatment phase <NUM>, <NUM>, and for charge, current and power balance, as described above. More generally, any waveform <NUM> or other waveform described here can be modulated to provide any number of positive, negative or bipolar pulses over any number of consecutive phases, in which each individual pulse may have a nominal, increased or decreased pulse width W = WO, Wi, Wj, etc..

<FIG> is an amplitude-time plot of a waveform <NUM> with matched on-off pulse width modulation. In this example, the pulse amplitude is fixed at an arbitrary nominal value A = A0, as shown on the vertical axis, with variable pulse widths Wi, Wj along on the horizontal, also in arbitrary units.

The pulses <NUM> making up waveform <NUM> are distributed among a number of consecutive phases <NUM>, <NUM>, with either positive or negative polarity as shown. The "on" pulse width W = Wi, Wj of each individual pulse <NUM> matches that of the corresponding "off" pulse segment <NUM>, and the pulse period T ("on" + "off") varies accordingly (e.g., Ti = <NUM> × Wi, Tj = <NUM> × Wj, etc.).

In this particular example the duty cycle of each individual pulse <NUM> is fixed at <NUM>%, since the widths of the on and off pulse segments are matched, while the instantaneous frequency f varies with the total pulse period (f = <NUM>/Ti, f = <NUM>/Tj, etc.). The modulation function is constrained to achieve charge, current and power balance, and so that the total integrated pulse width and treatment time is the same in each consecutive phase <NUM>, <NUM>. More generally, any waveform <NUM>, or other waveform described here, can be modulated to have matched or unmatched on and off pulse widths, with fixed or variable pulse amplitude, pulse period, and carrier frequency.

<FIG> is an amplitude-time plot of a pulse-frequency modulated (PFM) waveform <NUM>, with randomized pulse period and frequency (RPF). In this example, the nominal amplitude of each pulse <NUM> is substantially constant (A = A0; vertical axis), with fixed "on" pulse width WO (horizontal axis, in arbitrary units). The carrier frequency is modulated by varying the length of the "off" pulse segment <NUM>, as reflected in the pulse period T = Ti, Tj, etc., and the instantaneous (pulse-by-pulse) frequency varies accordingly (e.g.; f = <NUM>/Ti, F = <NUM>/Tj, etc.).

As shown in <FIG>, a series of frequency modulated pulses <NUM> can be arranged into consecutive phases <NUM> and <NUM>, with either the same or alternating (e.g., positive and negative) polarity. Some pulses <NUM> have a less than nominal period Ti < T0, corresponding to a negative pulse period deviation δi(-) = -|T0 - Til, and a relatively higher instantaneous (pulse-to-pulse) frequency f > <NUM>/T0. Other pulses <NUM> have a greater than nominal period Tj > T0, corresponding a positive deviation Δj(+) = +|Tj - T0|, and a relatively lower instantaneous frequency f < <NUM>/T0.

In the particular example of <FIG>, the nominal "on" pulse width WO and amplitude A0 are substantially the same for each pulse <NUM> in waveform <NUM>. Thus, the modulation function need not be further constrained for charge, current and power balancing between successive phases <NUM> and <NUM>, as long as the number of pulses (N) is the same. The modulation function can also be constrained to preserve the phase application time N×T0, so that successive phases <NUM>, <NUM> are equally spaced in time. In other applications, the pulse width and amplitude of any waveform <NUM> or other waveform described here can also be modulated to provide different phase application times, either independently from the pulse period and carrier frequency, or in combination.

<FIG> is an amplitude-time plot of a pulse-amplitude modulated (PAM) waveform <NUM>, with randomized pulse amplitude (RPA). As shown in <FIG>, the amplitudes (A) of the individual pulses <NUM> vary according to a random or pseudorandom function, while the nominal pulse width WO remains substantially constant; e.g., the "on" pulse width WO may also be equal to the nominal width of the corresponding "off" pulse segment <NUM>, as shown.

In the particular example of <FIG>, the nominal period T = T0 is substantially the same for each individual pulse <NUM> in the pulse-amplitude modulated waveform <NUM>. Thus, the carrier frequency f = <NUM>/T0 is also substantially constant. In other applications, the pulse period and carrier frequency may vary, along with the number of pulses and individual pulse widths.

As shown in <FIG>, the amplitudes A = Ai, Aj of individual pulses <NUM> can vary with respect to the nominal value A = A0. Some pulses, for example, have a relatively lower amplitude Ai < A0, corresponding to a negative amplitude deviation Di(-) = -|A0-Ai|. Other pulses have a relatively greater amplitude Aj > A0, with a positive deviation Dj(+) = +|Aj - A0|. The amplitude modulation can be applied in the same sequence to each phase, so that the amplitudes Ai, Aj of the individual pules <NUM> are the same in the first (e.g., positive) phase <NUM> and the second (e.g., negative) phase <NUM>, in the same order, or the amplitude modulations can be applied in any sequence, so that that the individual pulse amplitudes Ai, Aj vary in each phase <NUM>, <NUM>, in any order.

The randomized modulating function applied to pulse-amplitude modulated (PAM) waveform <NUM> can be constrained so that the integrated pulse amplitude is constant over each successive pulse train or treatment phase <NUM>, <NUM>, in order to achieve charge and current balancing. Similarly, the modulation function can be constrained to deliver the same integrated power over successive phases <NUM> and <NUM>, and so that the net integrated charge and current are substantially zero (or approach zero within a selected minimum of threshold value, as described above). Alternatively, the modulation function may be unconstrained, and the integrated amplitudes of any waveform <NUM> or other waveform described here may vary from pulse to pulse and from phase to phase, along with the applied voltage, current and power.

<FIG> is an amplitude-time plot of a waveform <NUM> with a combination of randomized pulse-width (RPW) modulation, randomized pulse amplitude (RPA) modulation, and randomized pulse frequency (RPF) modulation. In this particular example, the pulse width (W) and amplitude (A) vary among the individual pulses <NUM>, as well as the pulse period (T) and corresponding instantaneous carrier frequency f = <NUM>/T. The number of individual pulses (N) can also vary, as distributed among the successive (e.g., positive and negative polarity) phases <NUM> and <NUM>.

As shown in <FIG>, a randomized modulating function is applied to waveform <NUM> in order to vary the widths Wi, Wj of individual pulses <NUM> with respect to the nominal width WO. The modulation function can also be adapted to randomize the pulse amplitudes Ai, Aj, as defined with respect to the nominal value A0, and the instantaneous carrier frequency f = <NUM>/T, which varies according to the individual pulse periods Ti, Tj. The widths of the "off" pulse segments <NUM> may also vary, as the as defined with respect to the nominal "on" pulse width WO.

A single modulating function can be applied to randomize each of the selected pulse parameters, or a combination of modulating functions may be used. The modulation functions can also be adapted to maintain a fixed or constant pulse width, pulse amplitude, pulse period or frequency across the sequence of individual pulses <NUM> making up any one or more consecutive pulses <NUM>, in the same order, or the modulations can be applied in any sequence, combination, or order. Similarly, the number of individual pulses (N) may be the same in each sequential phase <NUM>, <NUM>, or the number of pulses (N) may vary from phase to phase.

Suitable randomized modulating functions can be constrained to maintain a constant integrated pulse amplitude over each successive phase <NUM>, <NUM>, in order to achieve charge, current and power balance. The modulation function can also be constrained to maintain a constant application time window N×T0 in each phase <NUM>, <NUM>, so that successive phases are equally spaced in time. Alternatively, the modulation function can be unconstrained with respect to the total pulse width or integrated pulse amplitude, or both, and the applied stimuli will vary accordingly.

<FIG> is a block diagram of a modulating function or method <NUM> for randomized pulse width modulation, suitable for use with any of the waveforms described herein. For example, the modulation function or method <NUM> can be applied to modulate a waveform in order to apply an electrical stimulus with a device <NUM> as shown in <FIG>, for microcurrent-based skin treatment according to method <NUM> of <FIG>, or for pulsed waveform modulation according to method <NUM> of <FIG>.

In the particular example of <FIG>, modulation function or method <NUM> includes one or more of a start block or process step <NUM> with one or more initiation sub-functions or steps <NUM>, <NUM>, <NUM> and <NUM>; a sequence randomization process block or step <NUM>; a start value process block or step <NUM> with one or more shift, set and count sub-functions or steps <NUM>, <NUM> and <NUM>; a pulse count block or step <NUM> with one or more output, system timer, delay and polarity toggling sub-functions or steps <NUM>, <NUM>, <NUM> and <NUM>; and a pulse increment process block or step <NUM> with one or more sequence, delay, and count increment sub-functions or steps <NUM>, <NUM> and <NUM>. These functions, sub-functions, process blocks and steps can be performed in any order or combination, with or without additional functions and techniques as described herein.

The function or method <NUM> can be initiated at a start operation or step <NUM>. The associated initialization steps <NUM>, <NUM>, <NUM> and <NUM> can be executed as process steps or sub-functions, in order to generate an initial pulse parameter vector or array PA characterizing a set of N pulses in the waveform or phase (initialize pulse array step <NUM>), and to generate an initial randomized (or other non-repeating) sequence vector or array RA characterizing a sequence in which the pulses may appear (initialize randomized sequence step <NUM>).

The pulse parameter array PA characterizes the pulse width of individual pulses in the waveform, or any combination of pulse parameters including pulse width, period, frequency and amplitude. The pulse amplitude parameters can be randomized according to the sequence array RA, or the individual parameter values can be randomized so that they are aperiodic, or varied in some other random, pseudorandom, non-repeating, aperiodic or predefined fashion. Some of the pulse parameters may also be fixed or substantially constant, for example in order to vary the pulse width (or other pulse parameter) independently of the others.

To initialize a start value (step <NUM>), the start value vector or array SA is set to zero (or other suitable initial value), for example to reference a prior or preselected starting sequence, or an initial set of randomized waveform parameters. More generally, the start value array SA can either be used to track either the individual waveform modulation values in modulation parameter array PA, or the randomized array RA (or other random, pseudorandom, or predefined array) indicating the sequence in which the varying pulse parameters are applied, in order to modulate consecutive pulses in the waveform.

To initialize pulse polarity (step <NUM>), a pulse polarity indicator PP is generated or defined. For example, a bipolar polarity indicator PP may be defined to designate the positive or negative phase of a modulated pulse application, or a unipolar indicated PP may be defined to indicate one or more sequential unipolar phases.

In the sequence randomization block (randomize sequence step <NUM>), the array RA characterizing the waveform sequence (step <NUM>) is filled with a randomized set of different values, indicating the sequence in which the array of pulse modulation parameters PA should be applied to modulate the waveform. For example, a set of pseudorandom integer numbers may be used to randomize the sequence in a non-repeating manner, or another ordered, non-repeating, aperiodic set of variables can be used, corresponding to sequence of N pulses in a given phase. Alternatively, the array of pulse modulations parameters PA can be generated or regenerated with a random, pseudorandom, or other non-repeating or aperiodic component, and the sequence in which they are applied can remain the same, or both the sequence and the parameters themselves may be randomized.

In the check start value block (step <NUM>), the randomized sequence array RA or pulse parameter array PA is compared to a corresponding start value array SA. If the randomized sequence is the same as the start value (or if the modulation parameters are the same), the sequence array RA can be shifted (shift sequence step <NUM>) in order to avoid repeating the same sequence. Depending on application, the randomized sequence array RA can be cyclically shifted one or more positions in either direction, or otherwise reordered, in order to change the sequence in which the pulse modulation parameter is array PA are applied to consecutive pulse. Alternatively, one or both of the modulation parameters (array PA) and the sequence (array RA) can be regenerated with a new set of randomized, pseudorandom, or other non-repeating or aperiodic values; e.g., by returning operation to the randomize sequence step <NUM>.

If the randomized sequence array RA is not the same as the start value array SA (or after it has been shifted or re-sequenced), the start value array SA is reset to the current randomized sequence array RA (set start value step <NUM>). Similarly, if the applied pulse modulation parameter array PA is not the same as the corresponding start value (or after it has been-re-randomized), the start value array SA can be reset to the current parameter array PA.

Thus, the start value array SA can be used to track either the most recent sequence in which the modulated waveform parameters PA are applied, or the actual parameter values themselves (or both). One the start value is updated (step <NUM>), the pulse count is reset to zero (step <NUM>), and successive pulses in the waveform can be counted out as they are applied.

The pulse count is checked at the start of the pulse count block (step <NUM>). If the count has not reached the number of desired pulses (N) in the phase or waveform, the next pulse can be output according to steps <NUM>, <NUM> and <NUM>. If the count has reached the number of pulses (N), the polarity indicator PP is switched (at toggle polarity +/- step <NUM>), before returning operation to the sequence randomization block (step <NUM>). For example, the polarity indicator PP can be toggled between positive and negative phases, or to indicate that a new phase is to be initiated in a unipolar application.

The waveform pulse is applied by setting the output high, and checking the system timer to determine the appropriate delay (step <NUM>). For example, a controller can be used to direct a voltage or current supply to apply a "high" or "on" signal to one or more electrodes, according to the desired pulse amplitude. The controller can also read or access the system clock or timer, in order to maintain the output amplitude for a delay time based on the desired pulse width or pulse duration (delay pulse duration step <NUM>).

The pulse width (and pulse frequency, period and amplitude) parameters used to modulate each successive pulse are determined from the pulse modulation parameter array PA, and applied in sequence to the consecutive pulses according to the randomized sequence array RA. Once the pulse has been output for the desired duration, the output is set to zero or other default "low" (or "off") value, at the output low step (block <NUM>).

The pulse count is checked again (step <NUM>), and, if the count has reached N-<NUM>, the random sequence array RA can be re-filled with pseudo-random integers or other ordered, non-repeating values, at fill sequence block (step <NUM>). Alternatively, the pulse parameter array PA can be reset with a new set of randomized, pseudorandom, or other non-repeating or aperiodic values (see randomize sequence step <NUM>).

At the delay pulse duration step (step <NUM>), the output low ("off') state is maintained for the desired duration, according the selected pulse width, period, or frequency parameter (delay pulse duration step <NUM>). Alternatively the pulse polarity can be reversed, in embodiments where bipolar pulses are applied.

The count is then incremented (count ++ step <NUM>), and the process returns to the check count block (step <NUM>). The function or method <NUM> can then be iterated until the desired number of pulses N has been applied in each polarity phase, and until the desired number of treatment phases are applied, or until the process is manually stopped (e.g., by the user).

<FIG> are front and side external views, respectively, showing embodiments of a representative skin treatment device <NUM> within a hand-held housing <NUM>. The housing <NUM> can be configured for enclosing a power supply <NUM> with a voltage or current generator (or source) <NUM>, as well as a microprocessor controller <NUM>, memory <NUM>, user interface <NUM> and other internal components; e.g., as described above with respect to <FIG>.

As can be seen in the particular embodiments of <FIG>, the elongated housing <NUM> can include a handle <NUM>; e.g., with a textured gripping area <NUM> and a skin contact head <NUM> formed at its upper end. The skin contact head <NUM> is shown as having at its outer face one, two or more electrodes 155A, 155B; e.g., with conductive surfaces that can be textured with a pattern to generate an electric stimulus or other energetic stimulus <NUM>; e.g., a microcurrent stimulus for delivery to a subject's skin. Suitable surface patterns are described, for example, in <CIT> (<CIT>.

In these particular examples, an outer electrode 155A is formed generally as an elliptical band that follows the outer periphery of the head <NUM> and encloses an elliptically shaped inner electrode 155B. In the center of electrode 155B is an area <NUM> that may contain one or more skin sensors and other environmental sensors <NUM>; e.g., as described above.

The use of programmed, randomized pulse width modulation (PRPWM) can have a variety of different biological effects, when the modulated waveform is applied as an electrical (e.g., voltage or current) stimulus to a subject's skin. These applications are distinct from those using an unmodulated or "un-randomized" (periodic or repeating) waveform, where the pulse width, pulse amplitude and pulse period may not vary from pulse to pulse, or across the individual pulses within a given treatment phase.

The beneficial effects of microcurrent skin stimulation using randomized pulse waveform modulation depend upon the applied stimulus. Generally, the microcurrent treatments disclosed here are insufficient to substantially increase skin temperature by resistive heating, or to induce directly electrochemical reactions or nerve and muscle stimulation, due to the low levels of applied voltage, current and charge. Other effects, however, may have both biological and electrochemical aspects. The benefits, moreover, are not necessary limited to cutaneous tissues in the skin itself, and may also extend to include the underlying subcutaneous layer. These effects may include, but are not limited to, changes in tissue resistivity, circulatory blood flow, connective tissue and collagen properties, and ATP (adenosine triphosphate) synthesis and amino acid uptake.

It is also well-established that electrical stimulation can change selected properties of skin tissue, which in turn can be characterized by changes in resistivity. For these effects, a few minutes of microcurrent stimulation can be sufficient to elicit desired changes, when applied within the voltage, current and power ranges disclosed here. Since the disclosed devices and methods can be applied in a unipolar or bipolar mode, moreover, these effects may be responsive both to the net charge, current or power applied in each treatment phase, and to the total charge, current and power applied over a complete treatment cycle.

For example, studies have confirmed increases in circulatory blood responsive to microcurrent stimulation, including treatments using an electrolyte solution or other treatment product applied topically to the skin. Increased circulation, in turn, has been linked to other beneficial biological effects, including improvements in capillary formation, healing, and nerve function.

Microcurrent skin treatments can also enhance the formation and regeneration of collagen and other connective tissues; e.g., in the epidermal, dermal, and subcutaneous tissue layers. Substantial results may also be seen after repeated treatment cycles, for example once or more daily, over a period of a few to several weeks or months. Studies have also shown that accelerated healing responsive to microcurrent therapies with alternating (reversed) positive and negative polarity phases, as disclosed here.

Microcurrent skin treatments have also been shown to enhance rates of cellular ATP production and amino acid uptake. The associated increases in cellular metabolism and protein synthesis rates may be related to enhanced collagen formation, as described above, and these benefits may accrue over treatment periods of a few weeks or more, with integrated treatment cycle times approaching two or more hours.

As explained above, the skin's response to an electrical stimulus depends on both the net charge or current delivered per treatment phase, and the total charge or current delivered over a full treatment cycle, including a number of sequential phases having the same or opposite polarity. The tendency for homeostasis may reduce the skin's response, however, when subject to a more constant or strictly periodic stimulus. Such a stimulus may also cause tissue to develop a corresponding periodic response to preserve a state of homeostasis in the skin tissue, which the body senses is being disrupted. Modulating the electrical pulses that are applied to the skin with a random or pseudorandom component makes the pulses aperiodic, and randomized pulse width, amplitude, and period modulation may reduce the tendency for homeostasis or preservation of homeostasis. The beneficial effects may also be manifested by changes in resistivity, circulation, and ATP synthesis, which can in turn may benefit collagen formation and connective tissue properties.

The inventive systems and techniques disclosed here are amendable to different modifications and alternative forms. Specific applications are described by way of examples, and described in detail. Practice of the invention, however, is not limited to these particular examples and embodiments, and the scope of the invention includes any and all modifications, equivalents, and alternatives falling within the scope of the invention as claimed. In these various embodiments, the invention comprises any suitable combination of the elements described herein, and as recited in the claims, and the claims can be practiced in the absence of any element which is not specifically recited therein.

The general principle of providing an electrical stimulus to skin as described above can be extended to other energetic stimuli presented not only in an electrical form but also in other forms, in which energy may be presented to skin as a stimulus, such that the energy enters the skin tissue and can have biological effects. One example is the use of LEDs, low-power lasers or other emitters of electromagnetic radiation, generally called light, but which may also include or be presented as radio-frequency (RF), infrared (IR) or optical energy, or low-energy (near-UV) or other suitable ultraviolet (UV) light, or other visible or non-visible forms of light energy, from any suitable parts of the electromagnetic spectrum. Similarly, the stimulus can be provided in the form of acoustic energy, for example as subsonic, sonic, or ultrasonic stimulus. These various energetic stimuli are producible from an emitter, which is controllable to produce a modulated waveform with beneficial effects on the skin.

Such a controllable waveform can be modulated or controlled by causing one or more parameters of the waveform to be randomized or pseudo-randomized, as described herein. To the extent these modulation and controlled modulation and randomization techniques discussed above can be applied to electrical stimuli to project energy into skin with beneficial effects, the same or similar techniques can be applied to other energetic stimuli including, but not limited to, electromagnetic and acoustic stimuli, or any combination thereof. Thus, the principles discussed here can be applied in analogous manner by modulating a set of consecutive pulses in other energetic waveforms, where pulse widths of the consecutive pulses vary in a random or pseudorandom fashion.

These applications open up options for skin treatment in which other or additional biological processes in the skin are beneficially affected by introducing a suitable (e.g., low-level) energetic stimulus using the same or analogous waveform modulation techniques for the energetic stimuli transmitted to the skin from one or more emitters. For the reasons stated above, these other stimuli can also produce beneficial effects, and can be introduced to the skin to affect these and other biological processes.

For example, with respect to LED lights or other light energy directed to skin, the light or other electromagnetic energy output of the emitters can be presented in pulses, where the pulse width, period, frequency or amplitude of the consecutive pulses varies in a random, pseudorandom, or other aperiodic manner. Accordingly, the waveform control and modulation techniques described above are equally applicable to electrical, electromagnetic, and acoustic stimuli that involve voltage, current, light, sound and other forms of energetic stimuli, and combinations thereof, which can be generated, emitted and transmitted in a relatively focused manner onto, into, or through a limited skin area, or other suitable area of the skin selected for treatment.

The following examples describe experiments designed and performed to provide information on the efficacy and/or utility of the devices and methods described herein. In each example described here, references to an ageLOC LumiSpa Microcurrent Attachment device with PRPWM refer to such a device disclosed by the present disclosure, for example a microcurrent device with PRPWM, a microcurrent attachment with PRPWM, or a PRPWM microcurrent device, as described herein.

All of these examples were selected using appropriate inclusion and exclusion criteria, and are merely representative. Other examples and embodiments also exist, as described by the present disclosure, and as defined within the scope of the appended claims.

EXAMPLE <NUM>: Four-Week Clinical Study Using Microcurrent with PRPWM. The objective of this research was to observe and understand tolerability, use, comfort, and beneficial skin appearance efficacy associated with the use of a microcurrent device with PRPWM and a conductive gel containing: water (aqua), glycerin, pentylene glycol, carbomer, sodium hydroxide, and chlorphenesin, as compared to a control where the same conductive gel was applied but no microcurrent device was used.

The methodology was a Split-face study design. Subjects who met all of the inclusion criteria and none of the exclusion criteria and also who have not used any antiaging treatment skin care products were invited to the research center. Twenty subjects completed the evaluation. They were females, with skin types ranging from Fitzpatrick I-III, <NUM>-<NUM> years old. A Conductive Gel available from Nu Skin Enterprises, Inc. of Provo, Utah and having the above ingredients was applied to the whole face of each subject. An ageLOC LumiSpa Microcurrent Attachment device with PRPWM was used on one randomly-selected side of the face during a four-week period. The use instructions were: Once daily, apply the gel to the entire face. Use the device on the face, only on the one randomized side of the face, for <NUM> minute. Use of gel on both sides of the face prevents the gel itself from being a differentiating factor.

Following enrollment, subjects used the conductive gel over the entire face, but used the device on one randomized side of the face. The investigator and subjects assessed skin appearance on both sides and tolerability to provide a baseline value for comparison. A questionnaire was completed. Subjects were given a compliance diary and told to use the device as stated above. They were instructed on how to use the device and used the device for the first time at the research center under staff supervision.

Post-first application, the investigator and subjects assessed the subjects' facial skin separately for each (PRPWM treated and untreated) side of the face for device efficacy and tolerability. The following timepoints were defined: Baseline, Post-Application, and weeks <NUM>, <NUM>, and <NUM>.

Subjects were asked to return and did return to the research center at weeks <NUM>, <NUM> and <NUM>. Evaluations were completed at each timepoint: one by a clinical grader and the other by the subject's self-perception. The efficacy evaluations were done with a focus on multiple defined points of evaluation, including: tactile roughness, visual smoothness, global firmness, eye firmness, plumping, texture, fine lines, wrinkles, crow's feet, smile lines, cheek wrinkles, pigmentation, skin tone, jaw line contour, pores, radiance and overall.

The assessments were made on a <NUM> point scale: <NUM>=none, <NUM>=minimal, <NUM>=mild, <NUM>=moderate, <NUM>=severe. The tolerability evaluations were made in terms of irritation, stinging, burning, itching, peeling, and dryness. The assessments were made on a <NUM> point scale: <NUM>=none, <NUM>=minimal, <NUM>=mild, <NUM>=moderate, <NUM>=severe. The compliance diaries of subjects were checked at the evaluation timepoints.

<FIG> illustrate user self-perception results in percent change over baseline for a first set of skin treatment criteria (tactile roughness, visual smoothness, global firmness, eye firmness, plumping, and texture). Results are shown at post-application, and at week <NUM>, <NUM> and <NUM> timepoints, respectively, for skin receiving a treatment gel only (<FIG>), and for skin receiving the gel plus a PRPWM microcurrent device treatment, as described herein (<FIG>).

<FIG> illustrate clinical grader results in percent change over baseline for the first set of criteria, at each of the respective timepoints. The results are shown for skin receiving the treatment gel only (<FIG>), as compared to skin receiving the gel plus a PRPWM device treatment (<FIG>).

In <FIG>, each group of four adjacent bars represents the change from baseline in one of the first set of criteria, for the timepoints at post-application and weeks <NUM>, <NUM>, and <NUM>, respectively (bars running from left to right). Percentages above a bar indicate a change of statistical significance over the baseline, as determined for the respective treatment criterion and timepoint that the bar represents. Results for some criteria may indicate a greater effect based on user self-evaluation, at a given timepoint, while results for other criteria may indicate a greater effect based on clinical grading. Some results may also indicate that no substantial change was noted, based on either self-evaluation or clinical grading, rather than no observations having been made.

<FIG> illustrate user self-perception results in percent change over baseline for a second set of skin treatment criteria (fine lines, wrinkles, crow's feet, smile lines, and cheek wrinkles). Results are shown at post-application and week <NUM>, <NUM> and <NUM> timepoints, respectively, for skin receiving a treatment gel only (<FIG>), and for skin receiving the gel plus a PRPWM microcurrent device treatment, as described herein (<FIG>).

<FIG> illustrate clinical grader results in percent change over baseline for the second set of criteria, at each of the respective timepoints. The results are shown for skin receiving the gel only (<FIG>), as compared to skin receiving the gel plus a PRPWM device treatment (<FIG>).

In <FIG>, each group of four adjacent bars represents the change from baseline in one of the second set of criteria, for the consecutive timepoints. In one example, data are also shown for an additional timepoint at week <NUM>. Percentages indicate a change of statistical significance over the baseline, as determined for the respective treatment criterion and timepoint. Some results may indicate that no substantial change was noted, either for self-evaluation or clinical grading, rather than no observations having been made.

<FIG> illustrate user self-perception results in percent change over baseline for third set of skin treatment criteria (pigmentation, skin tone, jaw line contour, pores, radiance, and overall appearance). Results are shown at post-application and week <NUM>, <NUM> and <NUM> timepoints, respectively, for skin receiving a treatment gel only (<FIG>), and for skin receiving the gel plus a PRPWM device treatment, as described herein (<FIG>).

<FIG> show clinical grader results in percent change over baseline for the third set of criteria (pigmentation, skin tone, jaw line contour, pores, radiance, and overall appearance), at each of the post-application, week <NUM>, <NUM> and <NUM> timepoints. The results are shown for skin receiving the gel only (<FIG>), with comparison to skin receiving the gel plus the PRPWM device treatment (<FIG>).

In <FIG>, each group of four adjacent bars represents the change from baseline in one of the third set of criteria, for consecutive timepoints. Percentages a change of indicate statistical significance over the baseline, as determined for the respective treatment criterion and timepoint. Some criteria may exhibit a greater or lesser effect based on either user self-evaluation or clinical grading, and other results may indicate that no substantial change was noted (rather than no observations having been made).

Investigator Efficacy Assessment. The (blinded) investigator assessed the treated and untreated sides of the face separately. The difference vs. baseline analysis was identified as useful. Immediately after one use, both sides of the face generally demonstrated a reduction in roughness (<FIG>). This immediate effect could be due to the microcurrent gel that was used on both sides of the face, the microcurrent treatment, or both. The improvement in roughness on both sides of the face continued throughout the four weeks of the study.

At week <NUM>, no statistically significant differences were observed between the treated and untreated sides of the face, at least for the first and second sets of criteria (e.g., as shown by boldface data and/or reference lines in <FIG>, <FIG> and <FIG>). By week <NUM>, there was statistically significant improvement in general facial firmness (p=<NUM>), eye firmness (p=<NUM>), and overall facial appearance (p=<NUM>) in the treated versus the untreated facial side (first and third sets of criteria, <FIG> and <FIG>). These improvements continued into week <NUM>, with a statistically significant improvement in roughness (p=<NUM>), smoothness (p=<NUM>), facial firmness (p<<NUM>), eye firmness (p<<NUM>), plumping (p=<NUM>), texture (p=<NUM>), and overall facial appearance (p=<NUM>). Accounting for the young age of the subject population, as specified by the sponsor, the subjects noted important improvement in firmness and skin visual and tactile characteristics after four weeks of device use.

Subject Efficacy Assessment. Generally, the (unblinded) subjects did not note any statistically significant changes immediately after one device use. At week <NUM>, statistically significant improvement was noted by the subjects on the treated side of the face, in pore size (p=<NUM>) and radiance (p=<NUM>) (third set of criteria, <FIG>). The week <NUM> subject assessments demonstrated statistically significant improvement in eye firmness (p=<NUM>) (first set of criteria, <FIG>). By week <NUM>, other additional assessments became statistically significant, including smoothness (p=<NUM>), eye firmness (p=<NUM>), and pore size (p=<NUM>) (first and third sets of criteria, <FIG> and <FIG>).

The following represented efficacy endpoints:.

EXAMPLE <NUM>: Circulation/Bloodflow Procedures, Female Subjects. This was a one-day clinical study in healthy female volunteers to compare the effects on circulation/blood flow when using a microcurrent device with PRPWM along with a conductive gel and an investigation topical compared to baseline. The device used was the AgeLOC LumiSpa Microcurrent Attachment with PRPWM. The topicals used were: Nu Skin Conductive Gel (ingredients described above in Example <NUM>), and an investigational formulation called MC Boost "East" (ingredients: water, glycerin, butylene glycol, dimethicone, niacinamide, tetrahexyldecyl ascorbate, polyglyceryl-<NUM> distearate, jojoba esters, polyglyceryl-<NUM> polyricinoleate, phenoxyethanol, citrullus lanatus (watermelon) fruit extract, sodium acrylates copolymer, chlorphenesin, sodium PCA, lens esculenta (lentil) seed extract, beeswax, cetyl alcohol, acrylates/C10-<NUM> alkyl acrylate crosspolymer, xanthan gum, pyrus malus (apple) fruit extract, lecithin, ethylhexylglycerin, tetrasodium glutamate diacetate, sodium lactate, aminomethyl propanol, hydroxypropyl methylcellulose stearoxy ether, propanediol, sodium acetylated hyaluronate, sodium hyaluronate, potassium sorbate, sodium benzoate, pancratium maritimum extract, sodium hydroxide).

The study was a single-blind, split-face, randomized, clinical study with <NUM> subjects, each a healthy female volunteer, between the ages of <NUM> and <NUM> years, Fitzpatrick Type I-III. The following test articles were supplied by the Sponsor:.

Treatment procedure for Conductive Gel topical was as follows:.

Treatment procedure for MC Boost "East" topical: Study staff repeated steps <NUM>-<NUM> above on the subject's other cheek.

On study day <NUM> (baseline), subjects attended the test facility with a clean face, free of makeup. Prior to acceptance on the study, subjects provided written informed consent and were screened for study eligibility. Subjects were queried as to their medical history and any concomitant medications. Skin condition on the face was assessed and demographic information was collected.

Subjects acclimated for a minimum of <NUM> minutes to indoor temperatures prior to instrumental assessments. Subjects had an approximately <NUM>-inch (about <NUM>) diameter circle test site drawn on each side of their face by the investigator or designee prior to instrumental assessments. Subjects had baseline temperature readings and Laser Doppler instrumental assessments on both sides of the face within the test sites. Subjects had the application of test products and PRPWM device use conducted by the investigator or designee (see treatment procedure above). The side of the face treated with the Conductive Gel was randomized to the right or left side of the face. Following the treatment to each side of the face, the subjects repeated the same instrumental assessments on both sides of the face.

The instrumental and visual assessments included:.

<FIG> are a table and bar chart, respectively, summarizing data from the laser Doppler assessments. In the bar chart of <FIG>, there are three pairs of bar graphs. The left-hand bar in each pair shows data for the conductive gel (from Example <NUM>), and the right-hand bar in each pair shows data from the MC Boost "East" gel (described above).

<FIG> are a table and bar chart, respectively, summarizing the data from the temperature assessments. Again, the left-hand bar in each pair shows data from the conductive gel (from Example <NUM>), while the orange or right-hand bar in each pair shows data from the MC Boost "East" gel (described above).

Study conclusions: Between-treatment and within-treatment analyses were conducted on changes from baseline for mean flux (blood flow) and facial temperature assessments. Within-treatment analyses showed a statistically significant decrease from baseline for both mean flux and temperature for both treated sites. There were no statistically significant differences between treatments for either mean flux or temperature. While not being bound by theory, it is believed that the decreases may have been caused by vasoconstriction, but the mechanisms for vasoconstriction in the circumstances of the experiment are not currently completely understood.

EXAMPLE <NUM>: Male subjects tolerability study. An important aspect of microcurrent treatment of facial skin is tolerability. Treatment with microcurrent is typically not acceptable if it is substantially uncomfortable or painful, or, for some persons, producing even mild discomfort. To study tolerability of a microcurrent attachment with PRPWM this study was performed with a sample of male subjects, in connection with shaving.

It is known that freshly shaved skin typically is more sensitive than other skin. Six male participants between ages <NUM>-<NUM> completed a comparative evaluation using a microcurrent attachment with PRPWM and also using a Nu Skin ageLOC Galvanic Spa. The latter provides low levels of direct current to the skin. While conductive conditions and sensitivity vary from person to person, and on any applied lotion or other material, a Nu Skin ageLOC Galvanic Spa typically provides current two and a half times lower than the current needed to produce only a slight sensation.

Participants in the tolerability study shaved with their own shave cream/gel/topical and razor and were provided with a microcurrent attachment with PRPWM and also a Nu Skin ageLOC Galvanic Spa. Immediately post-shave, participants used the ageLOC Galvanic Spa on setting <NUM> on one side of their face (cheek area). An observing clinical investigator noted how long the subject was able to tolerate the device comfortably. Participants then used the ageLOC Galvanic Spa on setting <NUM> on the same side of their face (cheek area). Again, the observing clinical investigator noted how long the subject was able to tolerate the device comfortably. After use of the ageLOC Galvanic Spa on settings <NUM> and <NUM>, participants used the ageLOC LumiSpa Microcurrent Attachment device with PRPWM on the other side of their face. Again, the observing clinical investigator noted how long the subject was able to tolerate the device comfortably.

<FIG> is a table summarizing data from the male subject tolerability study in Example <NUM>. The table in <FIG> shows the results observed by the clinical investigator for the three different current treatments described in the preceding. It should be noted that ageLOC Galvanic Spa on setting <NUM> is a positive polarity microcurrent, and the current can self-set to <NUM> mA, <NUM> mA, or <NUM> mA (± <NUM>%). The self-setting is based on the capacitance of the skin in the area touched, the environmental conditions at the time and the physiological conditions of the subject's skin at the time of application.

When ageLOC Galvanic Spa is on setting <NUM> there is a negative polarity microcurrent, and the current can self-set to the same levels as for setting <NUM>. Setting <NUM> has a duration of <NUM> minutes and setting <NUM> has a duration of <NUM> minutes, but the user can remove the device from the skin at any time. Some users shortened treatment, as shown in the table.

The results in Example <NUM> showed that by comparison to treatment with the two settings (<NUM> and <NUM>) of the ageLOC Galvanic Spa, the ageLOC LumiSpa Microcurrent Attachment device with PRPWM was more tolerable; i.e., it was perceived as more gentle on freshly shaved skin. Specifically, the PRPWM microcurrent treatment device was tolerable without discomfort for a <NUM> second treatment cycle, while the ageLOC Galvanic Spa on setting <NUM> could be tolerated for between one and three seconds by the subjects using setting <NUM>. For ageLOC Galvanic Spa on setting <NUM>, one subject tolerated up to <NUM> seconds, and the remainder tolerated <NUM> to <NUM> seconds.

Representative device applications, examples and embodiments include one or more emitters configured for application of a stimulus to a skin surface of a subject, a voltage source or current supply, and a computer-based controller. The voltage source or current supply can be adapted to generate a waveform for application of the stimulus to the skin surface of the subject, via the one or more emitters. The controller can be configured with memory and processor hardware adapted for modulating a set of consecutive pulses in the waveform.

In any of these applications, examples and embodiments, the set of consecutive pulses can define a treatment cycle having one or more phases; e.g., with each of the phases defining a continuous subset of the consecutive pulses. The pulse widths or absolute integrated amplitudes (or other amplitude) of the consecutive pulses in each of the phases can vary in at least one continuous subset defining at least one of the phases, or in each of the subsets defining each of the phases, or over the set of consecutive pulses defining the treatment cycle, either alternatively or in combination. For example, the pulse widths or absolute integrated amplitudes may be non-repeating or aperiodic over one or more of the phases in the treatment cycle, or over each of the phases in the treatment cycle, or they may otherwise vary over one or more of the phases in the treatment cycle, or over each of the phases in the treatment cycle.

In any of these applications, examples and embodiments, the pulse widths or absolute integrated amplitudes (or other amplitude) of the consecutive pulses may vary in a predefined, randomized or pseudorandom sequence, so that the pulse widths or absolute integrated amplitudes are non-repeating in one or more of the phases, in each of the phases, or over the set of consecutive pulses defining the treatment cycle, alternatively or in any combination. The predefined, randomized or pseudorandom sequence may also be shirted or reordered between phases, or otherwise constrained to provide a same duty cycle over each phase, or to provide charge balance over two or more of the phases having consecutive pulses of opposite polarity, or both. The sequence can be shifted or reordered between phases, so that the pulse widths or absolute integrated amplitudes vary in a different sequence in two or more of the phases.

In any of these applications, examples and embodiments, the pulse widths and absolute integrated amplitudes (or other amplitude) of the consecutive pulses can be determined at least in part based on a random or pseudorandom number generator. The pulse widths and absolute integrated amplitudes of consecutive pulses can also comprise or include a random, predetermined, or pseudorandom component, so that the absolute integrated amplitudes of the consecutive pulses has a same absolute value over each subset of the consecutive pulses, defining two or more of the phases, or over each of the phases.

In any of these applications, examples and embodiments, the pulse width, period, frequency, or absolute integrated amplitude (or other amplitude) of the consecutive pulses may vary, in any combination. The variation can be aperiodic or non-repeating, so that the modulated parameter does not repeat at all, or does not repeat with any identifiable pattern or sequence, over a given set of pulses defining a treatment cycle, or over a subset of consecutive pulses defining a phase of the treatment cycle, or both.

In any of these applications, examples and embodiments, the variation in the modulated pulse parameter can be at least <NUM>% or at least <NUM>% of the nominal or average value of the parameter, or less, where the nominal or average value is determined across a subset of consecutive pulses defining a phase of a selected treatment cycle, or across the set of consecutive pulses defining the treatment cycle. The variation in the modulated pulse parameter can also be at least <NUM>% of the nominal or average value, for example up to <NUM>% of the nominal or average value, or up to <NUM>% of or up to two times the nominal or average value, in any order or combination with the lower limits of at least <NUM>% or at least <NUM>% of the nominal or average value of the parameter. The variation in the modulated pulse parameter can also extend up to ten times the nominal or average value, or up to one hundred times the nominal or average value, or more, in any order or combination with the other limits.

In any of these applications, examples and embodiments, the one or more phases can comprise a first phase (or one or more first phases) having a first continuous subset of the consecutive pulses with a first polarity and a second phase (or one or more second phases) having a second continuous subset of the consecutive pulses with a second polarity, opposite the first polarity. The absolute integrated amplitudes (or other amplitude) of the consecutive pulses can vary, so that the amplitudes are non-repeating or aperiodic across the subset of consecutive pulses defining each of the phases, or both, exclusively or inclusively, or non-repeating or aperiodic across the set of consecutive pulses defining the treatment cycle, or both, exclusively or inclusively.

In any of these applications, examples and embodiments, the subset of consecutive pulses in each phase can have a constant absolute integrated amplitude, or other constant amplitude. A period of the subset of consecutive pulses can be fixed, such that a frequency of the consecutive pulses is constant across one or more of the phases, or over each of the phases in the treatment cycle, or over the set of consecutive pulses defining the treatment cycle.

In any of these applications, examples and embodiments, a frequency of the subset of consecutive pulses in each phase can vary, so that a period of the consecutive pulses is non-repeating or aperiodic across one or more of the phases, or over each of the phases in the treatment cycle, or over the set of consecutive pulses defining the treatment cycle.

In any of these applications, examples and embodiments, each of the consecutive pulses can comprises a first segment having a first absolute integrated amplitude (or other amplitude); e.g., with a second segment having a second amplitude or no amplitude, where the first and second segments have a same width. Each of the consecutive pulses can comprise first and second segments with different widths.

In any of these applications, examples and embodiments, the one or more emitters can comprise at least one electrode disposed adjacent the skin surface. The waveform can comprise an electrical waveform adapted for application of the stimulus to the skin surface as a microcurrent treatment, emitted via the at least one electrode. The modulated waveform can be adapted to apply the microcurrent treatment directly to the skin surface, or through a conductive fluid disposed on the skin surface, or between the skin surface and the at least one electrode. A sensor can be configured to generate feedback responsive to propagation of the stimulus into or through the skin surface of the subject, for example with a sensor circuit couple to one of the emitters or using a separate sensor device, where the waveform is modulated based on the feedback to apply the microcurrent treatment to the skin surface through a fluid disposed on the skin surface, or between the skin surface and the at least one electrode.

Representative method applications, examples and embodiments include modulating a waveform for application of a stimulus to a skin surface of a subject. Suitable methods can include providing a device adjacent the skin surface of the subject, supplying a voltage or current adapted to generate a waveform for application of the stimulus to the skin surface, and modulating a set of consecutive pulses in the waveform; e.g., using one or more emitters configured for administering the stimulus to the skin surface.

In any of these applications, examples and embodiments, the set of consecutive pulses can define a treatment cycle having one or more phases; e.g., with each of the phases defining a continuous subset of the consecutive pulses. The pulse widths or absolute integrated amplitudes of the consecutive pulses can vary over at least one continuous subset defining at least one phase, or over the set of consecutive pulses defining the treatment cycle (e.g., across each of the subsets defining each of the phases). For example, the pulse widths or absolute integrated amplitudes may be non-repeating or aperiodic over the one or more of the phases, or over one or more of the continuous subsets of consecutive pulses defining each phase, or over the full set of consecutive pulses defining the treatment cycle, exclusively or in combination.

In any of these applications, examples and embodiments, the pulse widths or absolute integrated amplitudes (or other amplitude) of the consecutive pulses can vary in a predefined, randomized or pseudorandom sequence, so that the pulse widths or amplitudes are non-repeating or aperiodic over one or more of the phases, or over each of the phases, or over the set of consecutive pulses defining the treatment cycle. The sequence can be shifted or reordered between phases, so that the pulse widths or absolute integrated amplitudes (or other amplitudes) vary differently in the subsets of consecutive pulses defining two or more of the phases; e.g., varying in a difference sequence in two or more phases. The sequence can constrained to provide a same duty cycle over each phase, or over two or more phases, or to provide charge balance over two or more of the phases having consecutive pulses with opposite polarity, or both, exclusively or in combination.

In any of these applications, examples and embodiments, the absolute integrated amplitudes (or other amplitude) of the subset of consecutive pulses in each phase can vary, so that the amplitude is aperiodic or non-repeating across one or more of the phases, or over each of the phases, or across the subset of consecutive pulses defining each of the phases, or across the set of consecutive pulses defining the treatment cycle, exclusively or in any combination. A frequency of the subset of consecutive pulses in each phase can vary, so that a period of the consecutive pulses is non-repeating or aperiodic across each phase, or across the set of consecutive pulses defining the treatment cycle, exclusively or in combination.

A non-transitory, machine readable data storage medium can be provided with program code stored thereon. The program code can be executable by a microprocessor or other computing device, in order to operate a device or perform a method according to any of these applications, examples and embodiments.

Representative skin treatment system applications, examples and embodiments can also include one or more emitters configured for emitting a stimulus for application to a skin surface of a subject, a voltage source or current supply configured to generate a waveform for application of the stimulus to the skin surface, via the one or more emitters, and a controller configured for modulating a set of consecutive pulses in the waveform. The set of consecutive pulses can define a treatment cycle having one or more phases; e.g., with each of the phases defining a continuous subset of the consecutive pulses. The consecutive pulses can vary by pulse width, period, frequency or amplitude; e.g., in a random, pseudorandom, or preselected sequence, so that the consecutive pulses are non-repeating or aperiodic over the subset of consecutive pulses defining one or more of the phases, or over each of the phases, or over the set of consecutive pulses defining the treatment cycle, either exclusively or in combination.

In any of these applications, examples and embodiments, the one or more emitters can comprise one or more electrodes configured to emit the stimulus as an energetic voltage or current stimulus applied to the skin surface. The one or more emitters can comprise one or more transducers configured to generate the stimulus as an energetic subsonic, sonic, ultrasonic, or acoustic stimulus applied to the skin surface. The one or more emitters can comprise one or more LEDs, lasers, or other electromagnetic sources configured to generate the stimulus as an energetic radio frequency (RF), infrared (IR), near-ultraviolet (near-UV) or ultraviolet (UV) stimulus. The one or more emitters can comprise any combination of such electrodes, transducers, LEDs, lasers, or other electromagnetic sources.

In any of these applications, examples and embodiments, the consecutive pulses can vary in a predefined, randomized or pseudorandom sequence, so that the consecutive pulses are non-repeating or aperiodic over at least one of the phases, or over each of the phases, or over the consecutive set of pulses defining the treatment cycle. The sequence can be constrained to provide a same duty cycle over each phase, or to provide charge balance over two or more of the phases having consecutive pulses with opposite polarity. The sequence can be shifted or reordered (e.g., between phases), so that the subsets of consecutive pulses provide a same duty cycle over each phase, or provide charge balance over two or more phases having consecutive pulses with opposite polarity.

In any of these applications, examples and embodiments, the waveform can be further modulated based on feedback responsive to propagation of the stimulus from the one or more emitters into or through the skin surface of the subject; e.g., via a topical agent applied between the emitters and the skin surface, or with a fluid (e.g., a conducting fluid) disposed between the emitters and the skin surface, or without such a topical agent or fluid.

A non-transitory, machine readable data storage medium can be provided with program code stored thereon; e.g., where the program code is executable by a microprocessor to operate a portable computing device, such as a smart phone, tablet, personal computer, or other user computing device. The portable computing device can be configured in communication with a device according to any of these applications, examples and embodiments; e.g., where the one or more emitters are configured for emitting the stimulus, the voltage or current supply is configured to generate the waveform, the controller is configured for modulating the set of consecutive pulses in the waveform, or the consecutive pulses are varied by pulse width, period, frequency or amplitude, by operation of the portable computing device.

Claim 1:
A device (<NUM>) comprising:
one or more emitters (<NUM>) configured for application of a stimulus (<NUM>) to a skin surface of a subject;
a voltage or current supply (<NUM>) adapted to generate a waveform for application of the stimulus (<NUM>) to the skin surface of the subject, via the one or more emitters (<NUM>); and
a controller (<NUM>) configured for modulating a set of consecutive pulses in the waveform, wherein the set of consecutive pulses defines a treatment cycle having one or more phases, each of the phases defining a continuous subset of the consecutive pulses;
wherein pulse widths or absolute integrated amplitudes of the consecutive pulses vary over at least one continuous subset defining at least one of the phases, or over the set of consecutive pulses defining the treatment cycle;
characterized in that the one or more emitters (<NUM>) comprise at least one electrode disposed adjacent the skin surface;
wherein the waveform comprises an electrical waveform adapted for application of the stimulus to the skin surface as a microcurrent treatment, emitted via the at least one electrode;
wherein the pulse widths or absolute integrated amplitudes of the consecutive pulses vary in a predefined, randomized or pseudorandom sequence, such that the pulse widths or absolute integrated amplitudes are non-repeating or aperiodic over one or more of the phases, or over the set of consecutive pulses defining the treatment cycle; and
wherein the sequence is constrained to provide a same duty cycle over each phase of two or more of the phases, or to provide charge balance over two or more of the phases having consecutive pulses with opposite polarity.