Method and system for percutaneous stimulation of muscle

Abstract

Methods and systems for percutaneous stimulation of muscles are disclosed. The method comprises or comprises: a) contacting a surface of skin near a target muscle with at least two electrodes; b) energizing the at least two electrodes to expose the target muscle to a first voltage having a first polarity for a first period of time; and c) energizing the at least two electrodes to expose the target muscle to a second voltage having a second polarity opposite the first polarity for a second period of time. The system and method can alter the polarity of the voltage exposed to the target muscle sufficient to stimulate the target muscle.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 392,916, filed on July 28, 2022, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to electrical stimulation of muscles, for example to treat or counter the effects of paralysis. Specifically, aspects of the present invention vary the polarity of the applied electrical stimulation to overcome the deficiencies and disadvantages of the prior art. Background Art

[0004] Electrical stimulation of the body for various purposes has been attempted since at least the 18th century. In the 1780s, Galvani first discovered that the muscles of dead frogs twitched when exposed to an electric spark. Benjamin Franklin reportedly tried to treat pain and other ailments with electric shocks. In the 1890s, Nicola Tesla experimented with treating the human body with electricity to treat a variety of ailments. In the 1970s, transcutaneous electrical nerve stimulation (TENS) was developed as a means of stimulating human nerves with electrical currents.

[0005] In the 1960s, functional electrical stimulation (FES) was introduced as a means of electrically stimulating human muscles to produce physical movement (for example, in patients suffering from paralysis). Since then, FES has been developed and used in a wide range of medical applications, including the treatment of conditions such as spinal cord injury, stroke, and muscular sclerosis.

[0006] However, it is recognized in the art that conventional FES therapy is limited by the pain that may be induced in a patient when FES is applied to the patient. For example, the application of relatively high voltages (e.g., voltages greater than 50 volts) may cause the patient to experience pain. Aspects of the present invention address this undesirable shortcoming of prior art methods.

[0007] It is generally understood in the art that when exposed to a voltage, the skin can be electrically viewed as a circuit with a capacitor and a resistor in series. For example, Kim et al. (2010) "A New Method for Non-Invasive Measurement of Skin in the Low Frequency Range" (Kim et al., PubMed, September 2010, the disclosure of which is incorporated herein) describes studies of the electrical properties of the skin.

[0008] Based on current understanding, it is believed that the capacitor-like electrical properties of the skin behave like any capacitor, i.e., when exposed to a DC voltage, current flows and the capacitor is charged, and then when one side of the capacitor reaches its positive charge, the current dissipation is zero. Based on this understanding, the "charging" of the skin "capacitor" may result in local polarization of the skin around the area where the electrode contacts the skin. Furthermore, it is believed that this local polarization of the skin may undesirably result in ions (e.g., positive ions) flowing from the electrode into the skin and / or from the skin to the electrode. Although it is not currently clear what the long-term effects of this ion flow are, it is generally believed that it may be harmful to the patient being treated. According to one aspect of the present invention, this polarization is minimized or prevented in the case where the ion flow between the electrode and the skin is minimized or prevented.

[0009] In further simulation of the capacitor-like properties of the skin, it can be speculated that when the voltage applied to the skin by the electrodes is varied, the frequency of the voltage variation affects the impedance of the skin. It is believed that the impedance of the skin to the voltage can manifest as pain to the patient being treated. Therefore, it can be speculated that reducing the impedance of the skin can reduce any pain that the patient may feel. For example, if a given current is required to generate a desired level of muscle stimulation, reducing the impedance of the current path through the skin by varying the voltage can reduce the voltage required to provide the desired current. Therefore, it is believed that varying the voltage and reducing the voltage can reduce the potential pain while providing the desired muscle stimulation because the voltage is lower.

[0010] For example, it is known in the art that the capacitive impedance XC of a capacitor such as skin is a function of the voltage frequency f and can be expressed as shown in Equation 1.

[0011] XC = 1 / (2πfC) Equation 1

[0012] C is the capacitance of the capacitor (i.e., the skin) in farads. Examination of equation 1 shows that as the frequency f of the applied voltage decreases, the impedance XC of the skin increases, and thus the degree of pain may increase. That is, the lower the frequency f, the higher the degree of pain for the patient. In addition to other advantages of the present invention, aspects of the present invention provide for applying voltage changes at relatively high frequencies (e.g., 1 kHz or higher), which can minimize or prevent the possibility of pain in the patient being treated.

[0013] In addition, according to various aspects of the present invention, and also with respect to Equation 1, wherein various aspects of the present invention can provide muscle stimulation voltages at higher frequencies, in addition to reducing the likelihood of pain, various aspects of the present invention can also reduce the impedance of the skin so that the current generated by the applied voltage can more effectively reach and penetrate the muscles that are the stimulation targets.

[0014] These and other advantages and benefits of the present invention will become apparent in various aspects from a reading of the following summary of the invention. Summary of the invention

[0015] As described herein, the present invention includes methods and systems for providing an alternating DC voltage to the skin adjacent to a stimulated muscle, wherein the polarity of the DC voltage is varied. It is believed that the change in polarity of the applied voltage minimizes or prevents polarization effects, reduces the likelihood of inducing pain, and increases effective stimulation of the stimulated muscle. In addition, aspects of the present invention can provide performance comparable to prior art muscle stimulation methods while reducing the energy required to achieve prior art performance.

[0016] One embodiment of the present invention is a method for stimulating a muscle, the method comprising or including: a) contacting the surface of the skin near a target muscle with at least two electrodes; b) energizing the at least two electrodes so that the target muscle is exposed to a first voltage having a first polarity for a first time period; and c) energizing the at least two electrodes so that the target muscle is exposed to a second voltage having a second polarity opposite to the first polarity for a second time period; wherein changing the polarity of the voltage to which the target muscle is exposed is sufficient to stimulate the target muscle.

[0017] In one aspect, the first voltage and the second voltage can range from 10 volts DC (VDC) to 300 VDC. In another aspect, the first voltage and / or the second voltage can be applied at a frequency between 1 kHz and 10 kHz.

[0018] In another aspect, the method can further include, between b) and c), de-energizing at least two electrodes to expose the target muscle to little or no voltage.

[0019] In another aspect, the method may further include, between b) and c), energizing at least two electrodes to expose the target muscle to a third voltage different from the first voltage and the second voltage.

[0020] In another aspect, the method may further comprise repeating b) a plurality of times before c), and / or repeating c) a plurality of times.

[0021] In another aspect, contacting the surface of the skin near the target muscle can be achieved by mounting at least two electrodes (eg, in the form of patches) in one or more packages and mounting the one or more packages to the surface of the skin.

[0022] Another embodiment of the present invention is a system for stimulating a muscle, the system comprising or including: at least two electrodes, the at least two electrodes being adapted to contact the surface of the skin near a target muscle; and an output device having at least two outputs, the at least two outputs being operably connected to the at least two electrodes, wherein the output device is configured to provide a first voltage having a first polarity for a first time period at one of the at least two sockets, and to provide a second voltage having a second polarity opposite to the first polarity for a second time period at another of the at least two sockets; wherein changing the polarity of the voltage to which the target muscle is exposed is sufficient to stimulate the target muscle.

[0023] In one aspect, the system may further include a high voltage generator, which is operably connected to the output device to provide the first voltage and the second voltage. For example, the high voltage generator can provide a voltage ranging from 10 VDC to 300 VDC.

[0024] In another aspect, the output device may be adapted to vary the frequency of at least one of the first voltage and the second voltage, for example, to a frequency in the range of 1 kHz to 10 kHz.

[0025] Another embodiment of the present invention is a wearable device having a system disclosed herein. In one aspect, the wearable device may include a patch having an adhesive suitable for at least temporarily adhering the patch to human skin. In another aspect, the wearable device may be mounted in clothing, equipment, or textiles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features and advantages of the invention will be readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a schematic block diagram of a system that can be used to implement aspects of the present invention.

[0028] Figure 2 is a schematic representation of a cross-section of a portion of the body having muscles that can be stimulated according to aspects of the present invention.

[0029] Figure 3 Is Figure 2 Details in 3 logo Figure 2 Detail of the cross section shown.

[0030] Figures 4 to 7 is a representative illustration of voltage polarity changes that may be provided according to aspects of the present invention.

[0031] Figure 8is a representative illustration of a wearable device having electrodes, a controller and a power button, and an alkaline battery according to aspects of the present invention.

[0032] Fig. 9 is a representative illustration of a controller having an on / off button and alkaline batteries according to aspects of the present invention.

[0033] Fig.10 is a representative illustration of electrodes according to aspects of the present invention.

[0034] Fig.11 The arrangement of components of a wearable device according to an embodiment of the present invention is exemplarily illustrated.

[0035] Fig.12 A fragment of the inner side of a garment to which electrodes are sewn according to an embodiment of the present invention is exemplarily illustrated.

[0036] Fig.13 The outer side of a garment and a segment of a first conductive thread extending at the outer side of the garment according to an embodiment of the present invention are exemplarily illustrated.

[0037] Fig.14 An insulating component provided on a first conductive line according to an embodiment of the present invention is exemplarily illustrated.

[0038] Fig.15 An end portion of a first conductive wire formed into a loop according to an embodiment of the present invention is exemplarily illustrated.

[0039] Fig.16 A first conductive wire passing through an insulating component for welding according to an embodiment of the present invention is exemplarily illustrated. DETAILED DESCRIPTION

[0040] Figure 1 is a schematic block diagram of a system 10 that can be used to implement various aspects of the present invention. According to one aspect of the present invention, the system 10 is suitable for generating and / or regulating a varying voltage and applying the varying voltage to a muscle or muscle group to be stimulated. In one aspect, the one or more muscles to be stimulated can be referred to as a "target muscle", and according to various aspects of the present invention, the target muscle is stimulated using a voltage (and / or a corresponding current) so as to, for example, promote contraction of the target muscle. According to various aspects of the present invention, contraction of the target muscle by controlled application of a voltage to at least a portion of the target muscle can be particularly used to stimulate contraction of target muscles when a patient loses the ability to stimulate muscles due to diseases such as spinal cord injury, stroke and / or muscular sclerosis and / or increase blood flow due to muscle stimulation.

[0041] like Figure 1As shown, the system 10 may generally include a processor 12 and an output device 14 adapted to receive instructions from the processor 12 via connection 13 and generate a plurality of outputs 11 (typically voltage outputs) to a plurality of electrodes 9 mounted on a body (not shown), such as a human or non-human body having muscles or muscle groups to be stimulated. The processor 12 may be any conventional processor, such as a microprocessor or computer known in the art, containing software and adapted to execute the software and generate control signals 13 forwarded to the output device 14. As is typical in the art, the processor 12 may be operably connected to an input device or user interface 16 (e.g., a keyboard, a pointer device, a controller, and / or a touch screen, etc.) via connection 17, and an output device or display 18 adapted to provide, for example, user feedback forwarded via connection 19 or display data generated by the processor 12. The system 10 may also generally include a data storage device 20 operably connected to the processor 12 via connection 21, the storage device being used to store data accessed by the processor 12 and / or to store data generated by the processor 12. Storage device 20 may include local or remote storage devices (e.g., storage locations accessed via a network, such as available in the "cloud" as known in the art), and may include fixed or removable storage media. For example, in one aspect, storage device 20 may be one or more removable "SD cards" or similar media as known in the art.

[0042] Likewise Figure 1 As shown, system 10 may generally include a low voltage generator 22 powered by power supply 23 and a high voltage generator 24 powered by power supply 25. Low voltage power supply 22 (e.g., a power supply suitable for providing a DC voltage of 0.5 volts to 5 volts) may power processor 12 via connection 26, may power output or display 18 via connection 27, may power input device 16 via connection 28, and may power storage device 20 via connection 19.

[0043] According to aspects of the present invention, the processor 12 can adjust and control the voltage output by the high voltage generator 24 via the connection 29, for example, 10 volts DC (VDC) to 300 VDC, to generate an output voltage to the output device 14 via the connection 30. For example, the high voltage generator 24 can be an inverter-based voltage generator using a step-up transformer or its equivalent. According to aspects of the present invention, the output device 14 is adapted to transmit the voltage generated by the voltage generator 24 to one or more sockets 11. According to aspects of the present invention, the voltage output by the one or more sockets 11 and the voltage change under the control and regulation of the processor 12 are applied to one or more electrodes 9 mounted on the body having the target muscle (e.g., the leg, arm or back muscle of a person), as described herein. For example, the output device 14 can include a multiplexer 32 or a "demultiplexer" known in the art, whereby the output device 14 can be adapted to selectively couple any one or more of the output voltages 11 with the voltage introduced from the high voltage generator 24 via the connection 30.

[0044] In one aspect, the output device 14 can be an inverter-based voltage generator or its equivalent. In one aspect, the output device 14 can also include a controller 34, which is suitable for monitoring and / or adjusting the voltage and / or current applied to the electrode 9 via the output 11. For example, the controller 34 can monitor and control the voltage outputted by the output device 14 and / or monitor the current outputted by the output device 14. In one aspect, the controller 34 can be suitable for detecting and / or adjusting the current delivered to one or more electrodes 9, for example, suitable for detecting and / or adjusting the current on a pulse-by-pulse basis. For example, in one aspect, the controller 34 can include a feedback loop, wherein the current directed to one or more electrodes 9 is detected, and then the voltage applied to one or more electrodes 9 is adjusted to achieve the desired current. For example, when the target current (e.g., 2 mA) is desired, the controller 34 can control the voltage output via the output 11 to maintain the target current. Therefore, in one aspect, if the detected current directed to one or more electrodes 9 is different from the target current, for example, due to a change in skin impedance (e.g., due to sweating or moisture causing impedance reduction), the controller 34 can change the voltage (e.g., reduce the voltage) to obtain the desired target current.

[0045] In one aspect, the output device 14 may include an oscillator adapted to switch a DC voltage into a transformer, for example, where the output voltage is processed in a manner similar to a switch mode power supply with a diode, such as a freewheeling Schottky diode or its equivalent.

[0046] According to aspects of the invention, one or more output voltages 11 may range from 10 VDC to 300 VDC, but are typically between about 40 VDC and about 100 VDC, such as about 60 VDC. In addition, the number N of outputs 11 may be unlimited, but may range from 2 outputs to 64 outputs; for example, N may range from 8 to 24 outputs, such as 16 outputs. The number of outputs N may vary depending on the number of target muscles being stimulated, the size of the target muscles, and / or the number of bodies being treated by aspects of the invention.

[0047] In one aspect of the invention, the processor 12 and / or controller 34 of the output device 14 may be adapted to control or regulate the voltage output by the output 11 and the frequency of the voltage output by the output 11. For example, in one aspect, the change in voltage polarity and / or amplitude may take the form of voltage "pulses" delivered at a frequency of, for example, 1 kHz or higher. In one aspect, the processor 12 and / or controller 34 of the output device 14 may be adapted to regulate and control the characteristics of the pulses, such as pulse amplitude, pulse polarity, pulse frequency, pulse width, time between pulses, number of pulses before or after a change in polarity, and other pulse characteristics. In one aspect, the processor 12 and / or controller 34 of the output device 14 may be adapted to provide pulse-by-pulse variation or control of the voltage provided by one or more outputs 11.

[0048] It is conceivable that Figure 1 Any one or more of the connections shown (including power and control signal connections) may include one or more wired and / or wireless connections, for example using any conventional wireless protocol, such as Bluetooth. wait.

[0049] Figure 2 4 is a schematic representation of an arrangement 40 of a cross-section of a portion of a body 42 having a target muscle 44 that can be stimulated according to aspects of the present invention. Figure 2 As shown, two or more electrodes 46 and 48 (e.g., having Figure 1 The electrode 9 shown has substantially the same characteristics as shown above and is mounted to the surface 50 of the skin 52 of a portion of the body 42. Figure 2 In the illustrated aspect, the portion of the body 42 is depicted as the lower portion of a human leg or calf to facilitate illustration of the present invention, but it is contemplated that aspects of the present invention may be used to stimulate any human or non-human muscle or muscle group. The muscles or muscle groups that may be stimulated include, but are not limited to, leg muscles, arm muscles, back muscles, trunk muscles, hand muscles, foot muscles, buttocks muscles, neck muscles, head muscles, and the like.

[0050] like Figure 2As shown, according to aspects of the present invention, two or more electrodes 46 and 48 are operatively connected to a voltage source, such as a voltage source, via wires or cables 47 and 49, respectively. Figure 1 The system 10 shown. Typically, when using a system such as Figure 1 When the system 10 is shown, the wires 47 and 49 can be electrically coupled or wired (i.e., hardwired or wirelessly connected) to Figure 1 Output device 14 is shown. Electrodes 46 and 48 are adapted to provide a voltage across at least a portion of target muscle 44 when energized. Figure 3 yes Figure 2 A detailed cross-sectional view of a portion of body 42 having electrodes 46 and 48 is shown in FIG. Figure 2 The details are shown in 3.

[0051] like Figure 3 As most clearly shown in the drawings, electrodes 46 and 48 can be mounted or enclosed in packages 54 and 56, respectively, for example, packages 54 and 56 can include flexible packages or "patches" as known in the art. Packages 54 and 56 can be mounted on a surface 50 of skin 52 adjacent to muscle 44. Packages 54 and 58 can include flexible materials and be mounted to the surface 50 of skin 52 in a conventional manner (e.g., removably mounted by adhesives known in the art). In one aspect, electrodes 46 and 48 can include any form of conductive material, such as a metal or a conductive plastic. Typically, electrodes 46 and 48 can include a conductive metal, such as silver, gold, or copper. In one aspect, as disclosed herein, any conventional electrode material and electrode packaging configuration can be used to contact surface 50 and apply a desired voltage.

[0052] According to various aspects of the present invention, Figure 1 The system 10 and electrodes 46 and 48 shown in FIG. 1 are suitable for exposing Figure 3 The target muscle 44 is used to generate an electric current (by Figure 3 4 (schematically represented by dashed line 60 shown in FIG. 4 ) to stimulate target muscle 44. Although the mechanism of current 60 is not well understood, it is contemplated that ions or electrolytes naturally present in the tissue of skin 52 and target muscle 44 transmit current from one electrode (e.g., electrode 46) to another electrode (e.g., electrode 48) to stimulate contraction of target muscle 44. According to aspects of the present invention, any form of conductive fluid, such as an electrolyte gel, may be applied between electrodes 46 and 48 and surface 50 of skin 52 to enhance exposure of target muscle 44 to the applied voltage.

[0053] like Figure 2 and Figure 3As shown and described, in one aspect, electrodes 46 and 48, as well as any other electrodes disclosed herein, can be in sufficient contact with the surface 50 of the skin 52 to expose the target muscle 44 to the applied voltage and transmit the current 60. That is, in one aspect, electrodes 46 and 48 can be operated "percutaneously" relative to the skin 52. However, in other aspects of the invention, electrodes 46 and 48, as well as any other electrodes disclosed herein, can penetrate the surface 50 of the skin 52, for example, at least partially penetrate the skin 52, to expose the target muscle 44 to the applied voltage and transmit the current 60. That is, in one aspect, electrodes 46 and 48 can be operated "subcutaneously" relative to the skin 52. For example, in one aspect, electrodes 46 and 48 can include one or more protrusions or "needles" (e.g., microneedles) 62 and 64 that penetrate the skin 42 to expose the target muscle 44 to the desired voltage disclosed herein. In one aspect, one or more protrusions or needles 62 and 64 can penetrate the target muscle 44 and expose the target muscle 44 to the desired voltage disclosed herein.

[0054] exist Figure 2 and Figure 3 In order to facilitate the description of one aspect of the present invention, various aspects of the present invention are shown, wherein electrodes 46 and 48 are located in packages or "patches" 54 and 56. However, it is contemplated that two or more electrodes 46 and 48 may be provided in a wide range of housings, packages, or "wearable devices" and the like while providing the benefits of the present invention. For example, two or more electrodes 46 and 48 may be provided in a "patch" having a plurality of electrodes 46 and 48, such as an array of electrodes 46 and 48. On the other hand, two or more electrodes 46 and 48 may be provided in a wearable housing (e.g., a housing held by a band or strap adapted to be mounted around a target muscle). For example, in one aspect, two or more electrodes 46 and 48 may be mounted in a watch-type device. On the other hand, two or more electrodes 46 and 48 may be provided in wearable clothing, such as in a shirt, in pants, or in a band adapted to be wrapped around a body part of a target muscle.

[0055] According to various aspects of the present invention, Figure 1 The system 10 is used to provide voltages of different polarities (eg, DC voltages) to stimulate target muscles (eg, Figure 3 Target muscles in 44). Figures 4 to 7 Representative illustrations of voltages, voltage changes, and voltage polarity changes that may be provided by aspects of the present invention are provided, for example, by Figure 1 The system 10 and Figure 2 and Figure 3 Electrodes 46 and 48 are shown provided.

[0056] Figure 470 is a representative graph of voltage as a function of time that may be applied to an electrode to stimulate a target muscle in accordance with aspects of the present invention. Graph 70 illustrates that in one aspect the applied voltage may be repeatedly varied (e.g., substantially instantaneously) in polarity and / or amplitude, for a fixed duration or for a varying duration.

[0057] exist Figure 4 In the graph 70, the ordinate 72 represents voltage, specifically, DC voltage, and the abscissa 74 represents time, such as milliseconds or minutes. Figure 4 As shown, in one aspect, the voltage that can be applied to the target muscle through various aspects of the present invention can include a first voltage 76 (e.g., 100 VDC) having a first polarity (e.g., positive (+)) for a first time period 78 (e.g., 5 milliseconds), followed by (e.g., substantially immediately thereafter) a second voltage 80 (e.g., 100 VDC) having a second polarity (e.g., negative (-)) opposite to the first polarity for a second time period 82 (e.g., 5 milliseconds) to expose the target muscle to sufficient stimulation.

[0058] According to various aspects of the present invention, it should be understood at this point that Figure 4 The change in voltage polarity shown in can minimize or prevent undesirable local polarization and ion migration, which is a feature of the prior art. For example, it is believed that Figure 4 The changes in voltage polarity shown in and throughout this disclosure counteract any charge accumulation that may occur compared to applying a continuous voltage or a voltage that does not change polarity. Therefore, it is believed that aspects of the present invention minimize or prevent undesirable ion migration, which is a feature of some prior art methods.

[0059] In one aspect, voltage 76 applied during time period 78 and voltage 80 applied during time period 82, as well as any voltage applied during time periods disclosed herein, may be referred to as a voltage "pulse." For example, Figure 4 The graph 70 in FIG. 70 may be described as illustrating a plurality of positive polarity pulses, each of which is substantially followed by a negative polarity pulse. As will be described herein, the order and timing of the positive and negative pulses may vary from Figure 4 as shown, while still providing the benefits of the present invention.

[0060] In one aspect, the voltage that produces sufficient stimulation includes a voltage that causes at least a partial contraction of the target muscle. In another aspect, the voltage that produces sufficient stimulation includes a voltage that causes a substantially complete contraction of the target muscle.

[0061] According to aspects of the present invention, the first voltage 76 and the second voltage 80 can range from about 10 VDC to about 300 VDC. In addition, the first time period 78 and the second time period 82 can range from about 1 microsecond (ps) to about 10 milliseconds (ms), but are typically between about 5ps and about 1ms. For example, in one aspect, Figure 4 The frequency of the voltage variation shown in the figure can range from about 200 Hz or 0.2 kHz to about 20 kHz, but is typically between about 1 kHz and 10 kHz. Therefore, the first time period 78 and the second time period 82 can range from about 0.005 seconds (i.e., 5 ms) to about 0.00005 seconds (i.e., 50 ps).

[0062] Furthermore, it is believed that such relatively high frequencies (e.g., greater than 1 kHz) Figure 4 The aspects shown and any aspects disclosed herein) can effectively reduce the capacitive impedance XC of the treated skin and thereby reduce the likelihood of pain and increase the effectiveness of target muscle stimulation.

[0063] like Figure 4 As shown, the sequence and timing of the first voltage 76 and the second voltage 80 can be repeated, for example, multiple times. Figure 4 In the sequence and timing shown in (or for any sequence and timing disclosed herein), the pulse can be applied for 1-5 seconds, then the voltage pulse can be stopped (e.g., for a "rest period") for, for example, 5 seconds to 5 minutes, and then the pulse is applied again. This apply-rest-apply sequence can be repeated as many times as needed or desired. In one aspect, the pulse is applied for 1-5 seconds, then the voltage pulse is stopped (e.g., for a "rest period") for, for example, 5 seconds to 5 minutes, and then the pulse is applied again. Figure 4 The treatment duration represented by graph 70 in (or for any sequence and timing disclosed herein) can be repeated for a total treatment time of 2 seconds to 30 minutes, but typically the treatment duration is 5 minutes to 15 minutes.

[0064] Despite Figure 4 1 and 10. Although not shown, it is contemplated that the first voltage 76 and the second voltage 80 can be substantially constant, or can vary between pulses. For example, in one aspect, the first voltage 76 and / or the second voltage 80 can vary linearly (increase or decrease), quadratically (increase or decrease), vary through any time-related variation, or vary irregularly. Furthermore, it is also contemplated that the time periods 78 and 82 can be substantially constant, or can also vary in duration.

[0065] exist Figure 4In the aspects of the invention shown (and in other figures herein), for ease of illustration, changes in voltage amplitude and polarity are shown as being substantially instantaneous, such as in a manner representing a step function. However, it is contemplated that changes in amplitude or polarity may not include such instantaneous changes, but rather the voltage and polarity may not change instantaneously, but rather gradually, such as linearly, due to system response or as needed. For example, in one aspect, the changes in the first voltage 76 and the second voltage 80 (or any voltage changes disclosed herein) may change linearly, quadratically, or at any defined or undefined time-dependent rate while providing the advantages and benefits of various aspects of the present invention.

[0066] Figure 5 90 is a representative graph of voltage as a function of time that may be applied to an electrode to stimulate a target muscle according to another aspect of the invention. Graph 90 illustrates that in one aspect the applied voltage may be repeatedly varied in polarity and / or amplitude, e.g., with time intervals between the variations. The time intervals may be of fixed duration or of varying duration.

[0067] exist Figure 5 In the graph 90, the ordinate 92 represents voltage, specifically, DC voltage, and the abscissa 94 represents time, such as milliseconds or minutes. Figure 5 As shown, in one aspect, the voltage that can be applied to the target muscle by various aspects of the present invention can include a first voltage 96 having a first polarity (e.g., positive (+)) in a first time period 98, followed by a second voltage 100 (e.g., 100 VDC) having a second polarity (e.g., negative (-)) opposite to the first polarity in a second time period 102, such that the target muscle is exposed to sufficient stimulation. In this aspect, as Figure 5 As shown, after the first voltage 96 and before the second voltage 100, the voltage applied to the electrode may include a third voltage 104 for a third time period 106, for example, a voltage that is substantially zero voltage. For example, in one aspect, the third voltage 104 can be provided by de-energizing at least two electrodes to expose the target muscle to very little or no voltage. In one aspect, the third voltage can be non-zero and can be positive or negative. In one aspect, the voltage that produces sufficient stimulation includes a voltage that causes the target muscle to at least partially contract. In another aspect, the voltage that produces sufficient stimulation includes a voltage that causes the target muscle to substantially fully contract.

[0068] According to various aspects of the present invention, Figure 5The voltages of the first voltage 96, the second voltage 100, and the third voltage 104 in the embodiment may be in the range of the first voltage 76 and the second voltage 80, for example, from about 10 VDC to about 300 VDC. In addition, as with the time periods 78 and 82, the first time period 98, the second time period 102, and the third time period 106 may be in the range of from about 1 ps to about 10 ms. In one aspect, Figure 5 The frequency of the voltage changes shown in may range from about 500 Hz to about 20 kHz, but is typically between about 1 kHz and 10 kHz.

[0069] like Figure 5 As shown, the sequence and timing of the first voltage 96, the second voltage 100 and the third voltage 102 can be repeated, for example, multiple times. Figure 5 The treatment duration represented by graph 90 in FIG. 1 can be repeated for a total treatment time of 2 seconds to 30 minutes, but typically the treatment duration is 1 minute to 5 minutes.

[0070] Despite Figure 5 100. Although not shown, it is contemplated that the first voltage 96 and the second voltage 100 can be substantially constant, or can vary between pulses. For example, in one aspect, the first voltage 96 and / or the second voltage 100 can vary linearly (increase or decrease), quadratically (increase or decrease), vary through any time-dependent variation, or vary irregularly. Furthermore, it is also contemplated that the time periods 98, 102, and 106 can be substantially constant, or can also vary in duration.

[0071] Figure 6 1 is a representative graph 110 of voltage as a function of time that may be applied to an electrode to stimulate a target muscle according to another aspect of the invention. Graph 110 illustrates that in one aspect the applied voltage may be repeatedly varied in polarity and / or amplitude (e.g., with time intervals between variations), for a fixed duration or for a varying duration.

[0072] exist Figure 6 In FIG. 1 , the ordinate 112 of the graph 110 represents voltage, specifically, DC voltage, and the abscissa 114 represents time, such as milliseconds or minutes. Figure 6 As shown, in one aspect, the voltage that can be applied to the target muscle through various aspects of the present invention can include a first voltage 116 having a first polarity (e.g., positive (+)) during a first time period 118, followed by a second voltage 120 having a second polarity (e.g., negative (-)) opposite to the first polarity during a second time period 122 to expose the target muscle to sufficient stimulation. Figure 6In the illustrated aspect, after the first voltage 116 and the second voltage 120, the voltage applied to the electrodes may include a third voltage 124, e.g., a voltage that is substantially zero voltage, for a third time period 126. For example, in one aspect, the third voltage 124 may be provided by de-energizing at least two electrodes to expose the target muscle to little or no voltage. In one aspect, the third voltage may be non-zero and may be positive or negative. In one aspect, the voltage that produces sufficient stimulation includes a voltage that causes the target muscle to at least partially contract. In another aspect, the voltage that produces sufficient stimulation includes a voltage that causes the target muscle to substantially fully contract.

[0073] According to various aspects of the present invention, Figure 6 The voltage range of the first voltage 116, the second voltage 120, and the third voltage 124 in the embodiment may be the range of the first voltage 76 and the second voltage 80, for example, about 10 VDC to about 300 VDC. In addition, as with the time periods 78 and 82, the first time period 118, the second time period 122, and the third time period 126 may be in the range of about 1 ps to about 10 ms. In one aspect, Figure 6 The frequency of the voltage changes shown in may range from about 500 Hz to about 20 kHz, but is typically between about 1 kHz and 10 kHz.

[0074] like Figure 6 As shown, the sequence and timing of the first voltage 116, the second voltage 120, and the third voltage 124 can be repeated, for example, multiple times. Figure 6 The treatment duration represented by graph 110 in can be repeated for a total treatment time from 2 seconds to 30 minutes, but typically the treatment duration is 1 minute to 5 minutes.

[0075] Despite Figure 6 1 , but it is contemplated that the first voltage 116 and the second voltage 120 can be substantially constant, or can vary between pulses. For example, in one aspect, the first voltage 116 and / or the second voltage 120 can vary linearly (increase or decrease), quadratically (increase or decrease), vary through any time-dependent variation, or vary irregularly. Furthermore, it is also contemplated that the time periods 118, 122, and 126 can be substantially constant, or can also vary in duration.

[0076] Figure 71 is a representative graph 130 of voltage as a function of time that may be applied to an electrode to stimulate a target muscle according to another aspect of the invention. Graph 130 illustrates that in one aspect the applied voltage may be repeatedly applied as a "pulse" of a first voltage at a first polarity, and then repeatedly applied as a "pulse" of a second voltage at a second polarity opposite to the first polarity, e.g., with a time interval between pulses. The time interval between pulses may be of a fixed duration or of a varying duration.

[0077] exist Figure 7 In FIG. 1 , the ordinate 132 of the graph 130 represents voltage, specifically, DC voltage, and the abscissa 134 represents time, such as milliseconds or minutes. Figure 7 As shown, in one aspect, the voltage that can be applied to the target muscle may include repeatedly applying a first voltage 136 having a first polarity (e.g., positive (+)) in a first time period 138, and then repeatedly applying a second voltage 140 having a second polarity (e.g., negative (-)) opposite to the first polarity in a second time period 142, so that the target muscle is sufficiently stimulated. Figure 7 In the aspect shown, between each first voltage 136, a third voltage 144 (e.g., a substantially zero voltage (although in some aspects, the third voltage 144 can be a non-zero voltage of either polarity)) can be applied for a third time period 141. Similarly, as Figure 7 As shown, between each second voltage 140, a fourth voltage 146 (e.g., a substantially zero voltage (although in some aspects, the third voltage 146 can be a non-zero voltage of either polarity)) can be applied for a fourth time period 148. For example, in one aspect, the third voltage 144 and the fourth voltage 146 can be provided by de-energizing at least two electrodes to expose the target muscle to little or no voltage. In one aspect, the voltage that produces sufficient stimulation includes a voltage that causes the target muscle to at least partially contract. In another aspect, the voltage that produces sufficient stimulation includes a voltage that causes the target muscle to substantially fully contract.

[0078] Despite Figure 7 1, but it is contemplated that the first voltage 136 and the second voltage 140 can be substantially constant, or can vary between pulses. For example, in one aspect, the first voltage 136 and / or the second voltage 140 can vary linearly (increase or decrease), quadratically (increase or decrease), vary through any time-related variation, or vary irregularly. Furthermore, it is also contemplated that the time periods 138, 141, 142, and 148 can be substantially constant, or can also vary in duration.

[0079] According to various aspects of the present invention, Figure 7The voltage range of the first voltage 136, the second voltage 140, the third voltage 144, and the fourth voltage 146 in the embodiment may be the range of the first voltage 76 and the second voltage 80, for example, from about 10 VDC to about 300 VDC. In addition, as with the time periods 78 and 82 disclosed herein, the time periods 138, 141, 142, and 148 may range from about 1 ps to about 10 ms. In one aspect, Figure 7 The frequency of the voltage changes shown in may range from about 500 Hz to about 20 kHz, but is typically between about 1 kHz and 10 kHz.

[0080] In one aspect, Figure 7 The sequence and timing of voltages (eg, pulses) shown in the figure may be repeated, for example, multiple times. Figure 7 The first voltage 136 in is shown as being repeated three times, but it is contemplated that the first voltage 136 can be repeated 10 times or more or hundreds or thousands of times, for example, at a frequency ranging from 1 kHz to 10 kHz. Similarly, it is contemplated that the second voltage 140 can be repeated 10 times or more or hundreds or thousands of times, for example, at a frequency ranging from 1 kHz to 10 kHz. In one aspect, the first voltage 136 in FIG. 1 can be repeated 10 times or more or hundreds or thousands of times, for example, at a frequency ranging from 1 kHz to 10 kHz. Figure 7 The treatment duration represented by graph 130 in FIG. 1 can be repeated for a total treatment time of 1 second to 30 minutes, but typically the treatment duration is 1 minute to 5 minutes.

[0081] According to various aspects of the present invention, Figures 4 to 7 The voltage changes and timing shown in are presented as typical voltage applications that can be used for target muscle stimulation. However, it is conceivable that those skilled in the art will think of countless other changes and timings that are not shown herein, but for the sake of brevity, are not presented herein.

[0082] Figure 8 The device is a device having electrodes 152, a controller 154 having a power on / off button 156, and alkaline batteries 158 (such as Fig. 9 and Fig.10 1. A representative illustration of a wearable device 150 (shown in FIG. 1 ). The wearable device 150 may be a shirt. Here, this is a view of electrodes 152 on the inside (fabric lining) of the shirt. Electrode connections such as wires (not shown) to a controller 154 may be embedded in the fabric of the shirt. Fig. 9 is a representative illustration of a controller 154 having an on / off button 156 and alkaline batteries 158 . Fig.10 is a representative illustration of electrode 152 .

[0083] like Figures 8 to 10As shown, the wearable device 150 incorporates hardware components developed with useful software including algorithms and firmware, including electrodes 152, microelectronics (not shown), a controller 154 with an on / off button 156, and an alkaline battery 158. According to various aspects of the present invention, the controller 154 can be located at the user's wrist / hand. The controller 154 also has real-time firmware embedded in it. System 10 (such as Figure 1 The wearable device 150 described in the accompanying drawings embodies an innovative approach to utilizing functional electrical stimulation (FES).

[0084] In one aspect, the wearable device 150 incorporates electrodes 152 for pain relief and has wires (not shown) running along the arm to a controller 154. For example, the solution here is to wear it as a shirt liner (base layer) and wires (not shown) running along the sleeve to the user's wrist / hand. Further, the wearable device 150 is specifically designed for: (1) Neck / back pain during operational conditions of military equipment and flight environments, especially naval environments. A key aspect of this innovation is that the wearable device 150 is powered by alkaline batteries 158 (not lithium batteries) that will be used in aircraft / flight environments. Lithium batteries are dangerous in flight environments and can generate dangerous levels of heat, which can easily cause ignition, short circuits, and lead to unextinguishable fires. This aspect of the invention provides a solution for user neck / back pain during military or normal passenger flight operations. In addition, the wearable device 150 can also be used in all environmental conditions in the civilian market.

[0085] Fig.11 The arrangement of components of a wearable device 150 according to an embodiment of the present invention is exemplarily illustrated. In one embodiment, the wearable device 150 is a garment. Typically, a garment includes an outer side and an inner side. The inner side refers to the side that contacts the wearer's body. The outer side refers to the side that is exposed to the environment. The device 150 includes one or more electrodes 152 and a controller 154 connected to the electrodes 152. The electrodes 152 are disposed at the inner side of the garment, and the controller 154 is disposed at the outer side of the garment.

[0086] The device 150 further includes at least one first conductive line 160. The first conductive line 160 extends between the controller 154 and the electrode 152 to electrically connect the controller 154 and the electrode 152. The first conductive line 160 extends at the outside of the clothing and electrically connects the controller 154 to the electrode 152. The device 150 is configured to prevent the first conductive line 160 from contacting the body. Further, the device 150 is configured in a manner that the first conductive line 160 only contacts the electrode 152. In one embodiment, the first conductive line 160 has a low resistance. The first conductive line 160 is used to transmit a signal from the controller 154 to the electrode 152. In one embodiment, the controller 154 uses a low voltage, such as 6V. Further, the present invention uses a functional electrical stimulation (FES) device. For FES devices, the pulse width is typically between 150us and 30us. Further, a fuse is used to prevent high current circuit conditions. When something is short-circuited, a large current is generated. When a large current condition occurs, the fuse will blow, thereby protecting hardware and personnel. The controller 154 designs a current limiting circuit. In one embodiment, a transient voltage suppressor is used to protect the circuit from electrostatic discharge.

[0087] In one embodiment, an embroidery machine with a second conductive thread is used to construct the electrode 152. In one embodiment, the second conductive thread comprises a high resistance. However, the resistance is reduced by increasing the area of ​​the material. This is achieved by the circular shape of the electrode 152. In one embodiment, the circular shaped electrode 152 is provided at the garment. In another embodiment, the electrode 152 may have any other shape.

[0088] refer to Fig.12 According to an embodiment of the present invention, the inner segment 170 of the garment is sewn with at least two electrodes 152. In another embodiment, one or more electrodes 152 may be provided at the garment. Fig.13 A segment 180 of the outer side of a garment according to an embodiment of the present invention is exemplarily illustrated. Further, the first conductive thread 160 extends at the outer side of the garment.

[0089] refer to Fig.14 , the device 150 further includes an insulating component 164. The insulating component 164 includes an electrically insulating material woven on the first conductive wire 160. Fig.15 , the first conductive wire 160 is pulled through the beads 168 to form a loop.

[0090] refer to Fig.16 According to an embodiment of the present invention, the first conductive line 160 passes through the insulating component 164. The insulating component 164 limits the current flowing to the first conductive line 160. The insulating component 164 and the first conductive line 160 are enclosed by a cover 166. Figures 14 to 16 .

[0091] Wearable device 150 is a conductive bio-shirt that can be worn like regular underwear. The bio-shirt is adapted to conform to the body of the wearer. In one embodiment, the conductive thread is conductive, soft enough to conform to the body, has the properties of regular fabric, is machine washable, and can be used with a sewing machine or embroidery machine.

[0092] The material properties of the second conductive wire, the shape and diameter of the electrode 152, and the density (wire count) of the electrode 152 are selected to significantly reduce the resistivity of the electrode 152; thus, allowing sufficient current to stimulate the muscle. The relationship between the resistance and the cross-sectional area of ​​the second conductive wire can be expressed as follows:

[0093] R=(ρL) / A

[0094] Where ρ is the resistivity of the second conductive line, L is the length, and A is the cross-sectional area. In general, resistance is always inversely proportional to the cross-sectional area of ​​the conductor, which can be expressed as follows:

[0095] R∝(1) / A

[0096] This ratio shows that the resistivity and cross-sectional area of ​​the second conductive wire are the two main factors that determine the electrode resistance. The resistance problem is solved by using conductive wires. These conductive wires have a resistance of less than 300 ohms / meter.

[0097] When using conductive thread and an embroidery machine to make the electrode 152, the technical parameters are configured as follows: the electrode diameter is set to 38 mm, and the number of embroidery needles is set to 5000. The surface area of ​​the thread has increased, and therefore the resistance of the electrode 152 has been reduced to about 0.7 ohms.

[0098] Further, the conductive trace or first conductive wire 160 is used to transmit current from the controller 154 to the electrode 152. In contrast to the thin and flexible second conductive wire used to construct the electrode 152, the conductive trace is strong and rigid enough to handle the movement of the body. In addition, the first conductive wire 160 has a low resistivity to prevent the current from the controller 154 from being dissipated as heat. The conductive material has a low resistivity of 10 ohms per foot. To further reduce the resistivity (ohms / foot), two strands of the first conductive wire 160 are extended in parallel to reduce the resistance by half.

[0099] Considering that the electrode and the conductive trace are different materials, a method was developed to ensure that the two materials remain attached to each other during normal use. In addition, the interface between the two materials must have a low impedance connection. In other words, current must be able to flow freely from one material to the other. This is achieved during construction by overlapping the conductive trace or first conductive thread 160 with the electrode thread or second conductive thread during the embroidery process.

[0100] Further, the first conductive line 160 is insulated, and as described below, the first conductive line 160 is transferred to the outside of the shirt. The outer portion of the shirt does not contact the body. Fig.12 As shown, a conductive first conductive thread 160 is attached to a second conductive thread on the inner half of the shirt. Fig.13 As shown, the loose end of the first conductive thread 160 is threaded to the outer half of the shirt. In this configuration, the shirt acts as a primary insulation. The first conductive thread 160 is held in a holder having a zigzag pattern created by a sewing machine, such as Fig.14 The final step of insulation is to cover 166 the first conductive thread 160 and the insulating component 164 using embroidery thread, as shown. Fig.16 This prevents the first conductive thread 160 from making electrical contact with anything that might be in contact with the outside of the shirt.

[0101] Another challenge of the present invention is disclosed as follows. Solder is a low melting point alloy used to connect metals that are not easily melted. Typically, in electronic devices, solder is used to connect wires and discrete components to PCBs (printed circuit boards). The soldering process allows current to flow from one device to another. In the case where the conductive wires cannot be soldered to the PCB of the controller, we must develop a reliable method to transition from the conductive wires to standard wiring at the PCB to interact with the controller. The solution and explanation of this challenge are as follows.

[0102] Due to the nature of the first conductive wire 160, it cannot be welded. Therefore, a technique was developed to transition from conductive wire to standard wire at the controller interface. The technique includes pulling the stainless steel first conductive wire 160 through the bead 168 to form a loop at step 1, such as Fig.15 As shown. At step 2, the controller wire is inserted through the loop of the first conductive wire 160 (also called the wire loop). At step 3, the conductive wire loop is pulled closer. At step 4, the bead 168 is crimped; thus, the first conductive wire 160 and the controller wire are fixed. At step 5, the interface including the bead, the controller wire and the conductive wire is welded. The result is shown in FIG. Fig.16 shown.

[0103] Further, in order for current to flow reliably from the controller 154 to the electrodes 152 and ultimately to the skin, good physical contact between the electrodes 152 and the skin must be achieved. This is addressed by constructing the shirt to be formed to "hug" the plate. This is like a tight-fitting garment. Additionally, elastic straps are placed near the electrode 152 locations to promote good physical contact between the electrodes 152 and the body.

[0104] Another challenge currently faced is the electrical contact between the electrode 152 and the skin. Basically, a poor electrical contact between the electrode and the skin will resemble a high impedance interface, which will result in poor current flow. Typically, when the skin is dry, a poor electrical connection occurs. The present invention solves this problem with a gel material and / or a conductive film.

[0105] Unlike existing "transcutaneous electrical nerve stimulation" (TENS) technology and existing "functional electrical stimulation" (FES) technology that use direct current (D / C), the electrical muscle stimulation technology incorporated in the wearable device 150 uses alternating current (A / C). For example, higher frequency and lower power A / C stimulation provides effective muscle stimulation (and function) without pain (compared to higher power D / C type stimulation), and can be used to stimulate muscle function in a wide range of applications.

[0106] According to various aspects of the present invention, A / C stimulation is more effectively transmitted to the target muscle "transcutaneously". In addition, because A / C stimulation can reach the subcutaneous muscle tissue more effectively, actual "functional stimulation" (muscle contraction) can be initiated. Unlike conventional D / C functional stimulation, A / C functional stimulation can be provided without increasing power, thereby avoiding pain caused by increased power, which is a characteristic of D / C stimulation. In fact, the present invention also proposes a method and device for painless, low-power initiation and control of muscle contraction.

[0107] For patients with skin sensation, TENS and traditional FES are limited by the patient's tolerance to stimulation pain, and assuming that the degree of pain is positively correlated with the voltage applied to the skin, the present invention will reduce pain because a lower voltage is required to produce a muscle stimulation FES pulse of a given current, thereby reducing the effective impedance of the skin by using an AC waveform in the delivery of stimulation. Thereafter, the present invention achieves the same FES current using a lower voltage.

[0108] According to various aspects of the present invention, an electrode output system is disclosed. The microcontroller can make the electrode pair any two (or more) electrodes, so the present invention provides a solution that can generate more complex stimulation. The present invention can alleviate the pain problem of FES by distributing the current delivered on multiple electrodes.

[0109] Although according to some aspects of the invention disclosed herein, voltage and voltage variation can be used alone to treat patients, in other aspects, the voltage variation stimulation disclosed herein can be supplemented with exposure to heat, humidity and / or information. One or more of these supplementary treatments can enhance the effectiveness of the voltage stimulation disclosed herein. The supplementary treatment can be applied together with the voltage stimulation disclosed herein, for example, applied substantially simultaneously or intermittently with the voltage stimulation.

[0110] According to aspects of the present invention, the changes in voltage and polarity stimulation disclosed herein can effectively stimulate muscles that would not otherwise respond to the patient's nervous system. For example, aspects of the present invention can effectively stimulate muscles affected by spinal cord injury, stroke and / or muscular sclerosis, among other diseases. However, aspects of the present invention overcome the shortcomings of the prior art, including the potential for undesirable ion migration and pain.

[0111] Although various embodiments have been described above, it should be understood that they are presented by way of example and not limitation. Various changes can be made in form and detail without departing from the spirit and scope of the present invention to those skilled in the relevant art. After reading the above description, it will be apparent to those skilled in the relevant art how to implement alternative embodiments.

[0112] In addition, it should be understood that any drawings highlighting features and advantages are presented for illustrative purposes only. The disclosed methods and systems are flexible and configurable enough that they can be utilized in ways other than those shown. Although the term "at least one" may often be used in the specification, claims, and drawings, the terms "one", "an", "the", "said", etc. also mean "at least one" or "the at least one" in the specification, claims, and drawings. Although several aspects of the present invention have been described and depicted herein, those skilled in the art may implement alternative aspects to achieve the same goals. Therefore, the appended claims are intended to cover all such alternative aspects that fall within the true spirit and scope of the present invention.

Claims

1. A method for stimulating muscles, the method comprising: a) contacting the surface of the skin near the target muscle with at least two electrodes; b) energizing the at least two electrodes to expose the target muscle to a first voltage having a first polarity for a first period of time; as well as c) energizing the at least two electrodes to expose the target muscle to a second voltage having a second polarity opposite to the first polarity for a second period of time; Wherein changing the polarity of the voltage to which the target muscle is exposed is sufficient to stimulate the target muscle.

2. The method according to claim 1, wherein: The first voltage ranges from 10 VDC to 300 VDC.

3. The method according to claim 1, wherein: The first voltage includes a frequency of 1 kHz to 10 kHz.

4. The method according to claim 1, wherein: The method further includes, between b) and c), de-energizing the at least two electrodes so that the target muscle is exposed to little or no voltage.

5. The method according to claim 1, wherein: The method further includes, after c), de-energizing the at least two electrodes such that the target muscle is exposed to little or no electrical energy.

6. The method according to claim 1, wherein: b) is repeated multiple times before c).

7. The method according to claim 1, wherein: c) Repeat multiple times.

8. The method according to claim 1, wherein: Contacting a surface of the skin proximate the target muscle includes mounting the at least two electrodes in one or more packages and mounting the one or more packages to the surface of the skin.

9. The method according to claim 1, wherein: The method further includes monitoring a current directed to the at least two electrodes and varying at least one of the first voltage and the second voltage in response to the current.

10. The method according to claim 9, wherein: Changing at least one of the first voltage and the second voltage in response to the current includes changing at least one of the first voltage and the second voltage to maintain a target current.

11. A system for stimulating muscles, the system comprising: at least two electrodes adapted to contact a surface of the skin proximate a target muscle; as well as an output device having at least two outputs operably connectable to the at least two electrodes, wherein the output device is configured to provide a first voltage having a first polarity for a first time period at one of the at least two receptacles and to provide a second voltage having a second polarity opposite to the first polarity for a second time period at another of the at least two receptacles; Wherein changing the polarity of the voltage to which the target muscle is exposed is sufficient to stimulate the target muscle.

12. The system according to claim 11, wherein: The system further includes a high voltage generator operably connected to the output device to provide the first voltage and the second voltage.

13. The system according to claim 11, wherein: The first voltage and the second voltage range from 10 VDC to 300 VDC.

14. The system according to claim 11, wherein: The output device is further adapted to vary a frequency of at least one of the first voltage and the second voltage.

15. The system of claim 14, wherein: The frequency range is 1 kHz to 10 kHz.

16. A wearable device having the system according to claim 11.

17. The wearable device according to claim 16, wherein: The wearable device includes a patch having an adhesive adapted to at least temporarily adhere the patch to human skin, and wherein the wearable device is mounted in at least one of clothing, equipment, and textiles.

18. The system of claim 11, wherein: The system further includes a controller adapted to monitor a current directed to the at least two electrodes and adapted to vary at least one of the first voltage and the second voltage in response to the current.

19. The system of claim 11, wherein: The controller is adapted to vary at least one of the first voltage and the second voltage to maintain a target current.

20. A system for stimulating muscles, the system comprising: a wearable device comprising a textile portion and at least two electrodes, wherein the textile portion comprises an inner side adapted to contact a skin surface of a wearer and an outer side, wherein the electrodes are disposed at the inner side of the textile portion and adapted to contact the skin surface near a target muscle; an output device having at least two outputs operably connectable to the at least two electrodes, wherein the output device is configured to provide a first voltage having a first polarity for a first time period at one of the at least two receptacles and to provide a second voltage having a second polarity opposite to the first polarity for a second time period at another of the at least two receptacles; a controller disposed at the outer side of the textile portion, the controller connected to the output device and the electrodes, wherein the controller is adapted to monitor a current directed to the at least two electrodes and to vary at least one of the first voltage and the second voltage in response to the current; at least one first conductive thread extending from the controller to the wearable device at the outer surface of the textile portion to electrically connect the controller to the wearable device, wherein changing the polarity of the voltage to which the target muscle is exposed is sufficient to stimulate the target muscle; as well as a high voltage generator operably connectable to the output device to provide the first voltage and the second voltage; and an insulating assembly comprising an electrically insulating material woven onto the first conductive wire.

21. The system of claim 20, wherein: The output device is further adapted to vary a frequency of at least one of the first voltage and the second voltage.

22. The system of claim 20, wherein: The controller is adapted to vary at least one of the first voltage and the second voltage to maintain a target current.

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