Non-invasive neural activator with boosted charge delivery

Abstract

A local nerve activation patch includes electronic circuitry embedded in the patch and configured to generate an output voltage applied to an electrode. The patch also includes a controller configured to generate a therapy comprising a plurality of activation pulses forming the output voltage, the therapy comprising electrical stimulation applied to a user via the electrode. The patch further includes a charge measurement circuit configured to measure an amount of charge applied to the user from the electrical stimulation and a communication link configured to communicate with a remote activation device comprising a second real-time clock. The controller is configured to generate the activation pulses by measuring a time interval using the oscillator and determining an activation time of the activation pulses using the second real-time clock and the measured time interval.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 948,780, filed December 16, 2019, the disclosure of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present invention relates to activating nerves by local stimulators to control or affect muscles, tissues, organs or sensations including pain in mammals including humans. BACKGROUND

[0004] Nerve diseases can result in loss of control of muscles and other body functions, loss of sensation or pain. Surgery and drugs sometimes treat these diseases, but have limitations. The present invention relates to a system for providing other options for treatment and improved function. BRIEF DESCRIPTION OF DRAWINGS

[0005] Figure 1 An example patch is illustrated that is to be affixed to a location behind the ankle bone of a user.

[0006] Figure 2 Is a block diagram of hardware / software related elements of an example of the patch of Figure 1

[0007] Figure 3A Is a circuit diagram of an example of a boost circuit that provides feedback.

[0008] Figure 3B Is a circuit diagram of an example of a charge application circuit that uses the output of the boost circuit.

[0009] Figure 4 Is a flow chart of the function of a controller that monitors and controls the output voltage, including its ramp rate.

[0010] Figure 5 Is a flow chart of one example of an adaptive protocol.

[0011] Figure 6 Is a differential integrator circuit used in an adaptive protocol according to one example.

[0012] Figure 7 Is a table relating charge duration to frequency for providing feedback to an adaptive protocol according to one example.

[0013] Figure 8 Illustrates a boost converter circuit that can be used in place of the boost converter circuit in the boost circuit of Figure 2 Illustrates a boost converter circuit that can be used in place of the boost converter circuit in the boost circuit of​

[0014] Figure 9 Charge monitoring circuitry for determining the charge delivered to a user by a patch is illustrated in other example inventions.

[0015] Figure 10 Closed loop circuitry for measuring the charge applied to a user is illustrated in example inventions.

[0016] Figure 11 And Figure 12 is a flowchart of a therapy monitoring function according to example inventions.

[0017] Figure 13 A stacked view of a patch according to example inventions is illustrated.

[0018] Figure 14 A stacked view of a patch assembly onto a substrate according to example inventions is illustrated.

[0019] Figure 15 Solid and patterned electrodes used in different examples of patches are illustrated. DETAILED DESCRIPTION

[0020] Non-invasive neural activators according to various examples disclosed herein include novel circuitry to boost voltage sufficiently to a desired level and maintain a substantially constant charge level for neural activation. In addition, feedback loops provide for automatic determination and adaptation of the applied charge level. Further, examples conserve battery power by selectively using battery power and form compact electronic packages to facilitate mounting on typically small adhesive external patches.

[0021] Figure 1 An example patch 100, also referred to as a smart bandage or smart pad or a topical neural activator (“TNA”) or a topical neural activation patch, is illustrated that is adhered to a location behind an ankle bone 110 of a user 105. In this example, the patch 100 is adapted to activate / stimulate the tibial nerve of the user 105, and can have one shape for a left ankle and a similar but mirrored shape for a right ankle. In other examples, the patch 100 is worn at different locations on the user 105 to activate the tibial nerve from different locations or to activate different nerves of the user 105. Figure 1

[0022] ​Patch 100 is used to stimulate these nerves and is convenient, unobtrusive, self-powered, and can be controlled by a smart phone or other control device. This has the advantages of being non-invasive, self-controlled by the consumer, and potentially over-the-counter distributed without a prescription. Patch 100 provides a means of stimulating nerves without penetrating the dermis and can be applied to the dermal surface at a location appropriate for the nerve of interest. In examples, patch 100 is applied by the user and is disposable.

[0023] Patch 100 in examples can be any type of device that can be fixedly attached to a user in some examples using an adhesive, and includes a processor / controller and instructions executed by the processor, or can also be a hardware implementation without software instructions, and electrodes and associated circuitry that apply electrical stimulation to the surface of the user’s skin. In one example, patch 100 provides localized nerve activation / stimulation on a user to provide a benefit to the user, such as bladder management for overactive bladder (“OAB”).

[0024] In one example, patch 100 can include a flexible substrate; a malleable dermal conforming bottom surface of the substrate including an adhesive and adapted to contact the dermis; a flexible top outer surface of the substrate generally parallel to the bottom surface; a plurality of electrodes positioned on the patch proximate the bottom surface and beneath the top outer surface and in direct contact with the flexible substrate; electronic circuitry (as disclosed herein) embedded in the patch and beneath the top outer surface and integrated as a system on a chip in direct contact with the flexible substrate, the electronic circuitry integrated as a system on a chip and including an electrical signal generator integral with the malleable dermal conforming bottom surface configured to electrically activate one or more electrodes, a signal activator coupled to the electrical signal generator, a nerve stimulation sensor providing feedback in response to stimulation of one or more nerves, an antenna configured to communicate with a remote activation device, a power source in electrical communication with the electrical signal generator, and the signal activator, wherein the signal activator is configured to activate in response to receipt of a communication with the activation device by the antenna and the electrical signal generator is configured to generate one or more electrical stimuli in response to activation by the signal activator, and the electrical stimuli are configured to stimulate one or more nerves of a user wearing patch 100 at least at a location proximate patch 100. Other details of examples of patch 100, in addition to the novel details disclosed herein, are disclosed in U.S. Patent No. 10,016,600 entitled “Topical Neurological Stimulation,” the disclosure of which is incorporated herein by reference.

[0025] Figure 2 is an illustration Figure 1A block diagram of the hardware / software related components of an example patch 100. Patch 100 includes electronic circuitry or a chip 1000 that performs the following functions: communicating with an external control device such as a smartphone or keychain (which can communicate with patch 100 via wireless communication such as Bluetooth Low Energy (“BLE”)) or external processing such as a cloud-based processing device; neural activation via electrodes 1008 that generate a wide-range electric field according to a treatment protocol; and a wide range of sensors 1006, such as, but not limited to, mechanical motion and pressure, temperature, humidity, acoustic, chemical, and positioning sensors. In another example, patch 100 includes a transducer 1014 to send signals to or receive signals from tissue.

[0026] One arrangement integrates a wide variety of these functions into a system-on-a-chip 1000. A control unit 1002 is shown for data processing, communication, transducer interface, and storage, along with one or more stimulators 1004 and sensors 1006 connected to electrodes 1008. The control unit 1002 may be implemented by a general-purpose processor / controller, or a dedicated processor / controller or dedicated logic circuitry. An antenna 1010 is incorporated for external communication via the control unit 1002. An internal power supply 1012 is also included, which may be, for example, a battery. The battery capacity may range from approximately 1 mA to approximately 100 mA. Other examples may include an external power supply. It may be necessary to include more than one chip to accommodate a wide range of voltages for data processing and stimulation, or one or more functions may be implemented on their own separate chip / electronic package. The electronic circuitry and chips will communicate with each other via conductive rails within the device capable of transmitting data and / or power.

[0027] Patch 100 interprets the data stream from control unit 1002 to separate message headers and delimiters from control instructions. In one example, the control instructions include information such as voltage level and pulse pattern. Patch 100 activates stimulator 1004 according to the control instructions to generate a stimulation signal to electrode 1008 placed on tissue. In another example, patch 100 activates transducer 1014 to transmit a signal to tissue. In yet another example, the control instructions cause information such as voltage level and pulse pattern to be retrieved from a library stored by patch 100 (such as a repository within control unit 1002).

[0028] Patch 100 receives sensory signals from tissue and converts them into a data stream that is recognized by control unit 1002. Sensory signals may include electrical, mechanical, acoustic, optical, and chemical signals. Sensory signals are received by patch 100 via electrodes 1008 or from other inputs originating from mechanical, acoustic, optical, or chemical transducers. For example, an electrical signal from tissue is introduced into patch 100 via electrodes 1008, converted from an analog signal to a digital signal, and then inserted into a data stream transmitted via antenna 1010 to an external control device. In another example, an acoustic signal is received by transducer 1014, converted from an analog signal to a digital signal, and then inserted into a data stream transmitted via antenna 1010 to an external control device. In some examples, sensory signals from tissue are directly interfaced with an external control device for processing.

[0029] In the example of patch 100 disclosed above, when used for therapeutic treatments such as bladder management of OAB, it is necessary to control the voltage by boosting the voltage to a selected level and providing the same level of charge when activating the mammalian nerves. Furthermore, it is necessary to conserve battery life by selectively using battery power. Additionally, it is necessary to create a compact electronic package to facilitate mounting the electronic package, in the size range of a common adhesive patch or bandage, onto a relatively small mammalian skin patch.

[0030] To meet the above requirements, an example implements a novel boost circuit that includes a feedback circuit and a charge application circuit. Figure 3A This is a circuit diagram of an example of a boost circuit 200 that provides feedback.

[0031] Figure 3B This is a circuit diagram of an example of a charge application circuit 300 using the output of a boost circuit 200. The boost circuit 200 includes both electronic components and a controller / processor 270, which includes a sequence of instructions that together modify the activation / stimulation voltage level delivered by the patch 100 to the external dermis of the user 105 via electrodes. The controller / processor 270 in this example... Figure 2 This is achieved through the control unit 1002.

[0032] The boost circuit 200 can replace a separate analog-controlled boost regulator by using a digital control loop to create a regulated voltage, output voltage 250, from a battery source. The output voltage 250 is provided as an input voltage to charge the application circuit 300. In this example, this voltage provides a nerve stimulation current through the dermis / skin to provide treatment for overactive bladder. The output voltage 250, or "VB," at the voltage output node 250... oost"Two digital feedback paths 220 and 230 are used via controller 270. In each of these paths, controller 270 uses a sequence of instructions to interpret the measured voltage, or 'V', at voltage monitor 226." ADC "and the quantity measured at current monitor 234 or "I ADC "and determine the appropriate output control for accurate and stable output voltage 250".

[0033] The boost circuit 200 includes an inductor 212, a diode 214, and a capacitor 216 that together implement the boost converter circuit 210. The voltage monitoring circuit 220 includes a top resistor 222 or "R". T ", Bottom resistor 224 or "R" B A resistor divider is formed by voltage monitor 226 and current monitoring circuit 230. Current monitoring circuit 230 includes current measuring resistor 232 or "R". I The circuit includes a current monitor 234. A pulse width modulation ("PWM") circuit 240 includes a field-effect transistor ("FET") switch 242 and a PWM driver 244. An output voltage 250 serves as a sink for electrical energy. An input voltage 260, or "V", is used. BAT It is the source of electrical energy, and can be generated by... Figure 2 This is achieved using a power supply of 1012.

[0034] The PWM circuit 240 alters the "on" time within the fixed-frequency digital square wave signal to change the ratio of the "on" to "off" time of the command power switch. In the boost circuit 200, the PWM driver 244 drives the FET switch 242 to the "on" and "off" states.

[0035] During operation, when FET switch 242 is turned on (i.e., conducted), the drain of FET switch 242 is drained to ground / GND or ground node 270. FET switch 242 remains on until its current reaches a level selected by controller 270, which acts as a servo controller. This current is measured as a representative voltage across current-measuring resistor 232, detected by current monitor 234. Energy is stored in the magnetic field within inductor 212 due to its inductance. Current flows through current-measuring resistor 232 to ground until FET switch 242 is turned on by PWM driver 244.

[0036] When the expected pulse width duration is reached, controller 270 disconnects FET switch 242. Current in inductor 212 is rerouted from FET switch 242 to diode 214, causing diode 214 to relay the current. Diode 214 charges capacitor 216. Therefore, the voltage level at capacitor 216 is controlled by controller 270.

[0037] The output voltage 250 is controlled using an external servo loop comprising voltage monitor 226 and controller 270. The output voltage 250 is measured using a resistive voltage divider with top resistor 222, bottom resistor 224, and voltage monitor 226. The values ​​of top resistor 222 and bottom resistor 224 are selected to maintain the voltage across bottom resistor 224 within the monitoring range of voltage monitor 226. Controller 270 monitors the output value from voltage monitor 226.

[0038] The charge application circuit 300 includes a pulse application circuit 310, which includes an enable switch 314. The controller 270 does not allow the enable switch 314 to be turned on unless the output voltage 250 is within a desired upper and lower range of its desired value. The pulse application circuit 310 is operated by the controller 270 by an assertion enable signal / voltage 312 or “VSW”, which turns on the enable switch 314 to allow electrical energy represented by the output voltage 250 to pass through the electrode 320 via the capacitor 316. The capacitor 316 isolates the electrode 320 from the DC voltage in the charging circuit as a safety feature in the device. Simultaneously, the controller 270 continues to monitor the output voltage 250 and controls the PWM driver 244 to turn the FET switch 242 on and off, maintaining the capacitor 216 at the desired value of the output voltage 250.

[0039] The stability of the output voltage 250 can be improved by an optional internal feedback loop via FET switch 242, current measuring resistor 232, and current monitor 234. Controller 270 monitors the output value of current monitor 234 at a faster rate than the monitoring on voltage monitor 226, minimizing voltage variations at the cathode of diode 214, thereby improving control over the voltage swing of output voltage 250 and load sensitivity.

[0040] As described, in this example, controller 270 uses multiple feedback loops to adjust the duty cycle of PWM driver 244 to create a stable output voltage 250 across a range of values. Controller 270 uses multiple feedback loops and monitors circuit parameters to control the output voltage 250 and evaluate the appropriate functioning of the hardware. Controller 270 operates according to feedback and monitored values ​​to provide improved patient safety and reduced electrical hazards by disabling erroneous electrical functions.

[0041] In some examples, controller 270 implements monitoring instructions using firmware or software code. In other examples, controller 270 implements monitoring instructions using a hardware state machine.

[0042] In some examples, voltage monitor 226 is an internal feature of controller 270. In other examples, voltage monitor 226 is an external component that transmits its digital output value to the digital input port of controller 270.

[0043] In some examples, the current monitor 234 is an internal feature of the controller 270. In other examples, the current monitor 234 is an external component that transmits its digital output value to the digital input port of the controller 270.

[0044] Compared to known circuits, the boost circuit 200 offers the advantage of reduced component count, leading to lower costs, smaller board size, and higher reliability. Furthermore, the boost circuit 200 provides centralized processing of all feedback data, resulting in faster response to faults. Additionally, the boost circuit 200 controls the input from V... BAT The 260 outflow current increases battery life and reliability.

[0045] Figure 4 This is a flowchart illustrating the function of the controller 270 that monitors and controls the output voltage 250 (including its ramp rate). In one example, Figure 4 and below Figure 5 , Figure 11 and Figure 12 The functionality of the flowchart is implemented by software stored in memory or other computer-readable or tangible media and executed by a processor. In other examples, the functionality may be implemented by hardware (e.g., by using an application-specific integrated circuit (“ASIC”), a programmable gate array (“PGA”), a field-programmable gate array (“FPGA”), etc.) or any combination of hardware and software.

[0046] The pulse width modulation of FET switch 242 is controlled by one or more pulses, each pulse width setting allowing more or less charge to accumulate as voltage through diode 214 at capacitor 216. This pulse width setting is called the ramp strength and is initialized at 410. Controller 270 uses a stage index initialized at 412 to sequentially enable each pulse group, one stage at a time, with a predetermined pulse width. The desired ramp strength is converted to a pulse width at 424, which enables and disables FET switch 242 based on the pulse width. During the interval when FET switch 242 is "on", the current is measured by current monitor 234 at 430 and checked against the expected value at 436. When the current reaches the expected value, the stage is complete and the stage index is incremented at 440. If the desired number of stages 442 has been applied, then the function is complete. Otherwise, the function continues to the next stage at 420.

[0047] because Figure 4The function of the V used in patch 100 BAT 260 will operate for longer periods because the current drawn from the battery ramps up at a lower rate, thus reducing the peak current required to achieve the final voltage level 250 for each activation / stimulation treatment. The duty cycle of PWM244 is adjusted by controller 270 to change the ramp strength at 410, thereby improving battery life.

[0048] In known neurostimulation devices, the open-loop protocol used to control the current flowing to the electrodes lacks feedback control. Its commands set the voltage, but the actual amount of current delivered to the user is uncertain. Stimulation pulses are sent according to preset parameters and are generally not modifiable based on feedback from the patient's anatomy. Electrode placement changes when the device is removed and repositioned. Humidity and temperature of the anatomy also vary throughout the day. If a voltage is preset, all these factors affect the actual charge delivery. Charge control is a crucial feature for patient safety and contributes to improved patient comfort, treatment consistency, and therapeutic efficacy.

[0049] As a contrast, an example of patch 100 includes features that address these drawbacks by using controller 270 to adjust the charge applied by electrode 320. Controller 270 samples the voltage of the stimulation waveform, providing feedback for an adaptive protocol and impedance calculations to modify the stimulation waveform in real time. A differential integrator is used to integrate and sample the current delivered from the stimulation waveform to the anatomical structure, and then summed to determine the actual charge delivered to the user for treatment (such as OAB therapy). After each pulse in a stimulation event, this data is analyzed and used to modify subsequent pulses in real time.

[0050] This hardware adaptation allows the firmware protocol to implement an adaptive protocol. This protocol works by changing the output voltage (“V”). BOOST Electrode 250 is used to adjust the electrical charge applied to the body. The treatment is performed through a series of periodic pulses that deliver the charge into the body via electrode 320. Some treatment parameters are fixed, while others are user-adjustable. Intensity, duration, and frequency can be user-adjustable. Users can adjust these parameters as needed for comfort and effectiveness. If there is discomfort, the intensity can be reduced, and if there is no discomfort, the intensity can be increased. If the maximum acceptable intensity results in ineffective treatment, the duration can be increased.

[0051] Adaptive protocol

[0052] Figure 5 The diagram shows a flowchart of an example of the adaptive protocol discussed above. The adaptive protocol aims to repeatedly and reliably deliver a target charge in coulombs (“Q”) during treatment. target(and take into account any environmental changes. Therefore,) Figure 5 Its function is to adjust the charge level applied to the user based on feedback, rather than using a constant level.

[0053] The mathematical expression for this protocol is as follows:

[0054] Q target =Q target (A*dS+B*dT), where A is an empirically determined intensity coefficient, dS is the user's intensity change, B is an empirically determined duration coefficient, and dT is the user's duration change.

[0055] In one example, the adaptive protocol comprises two phases: an acquisition phase 500 and a reproduction phase 520. Any change in user parameters will trigger the adaptive protocol during the acquisition phase. When the first treatment begins, a new reference charge is calculated based on the new parameters. In the new acquisition phase at 502, all data from previous charge applications is discarded. In one example, 502 indicates the first use of the current, where the user places patch 100 on a part of the body and manually adjusts the charge level as a series of charge pulses until it feels appropriate, or changes the charge level manually or automatically at any time. The treatment then begins. The mathematical expression for this charge application function is as follows:

[0056] The charge delivered during treatment is

[0057] Where T is the duration; f is the pulse count of a treatment (e.g., Hertz or cycles / second) as the "repetition rate"; Q pulse (i) is the measurement charge delivered by Pulse(i) in the treatment pulse train provided as a voltage MON_CURRENT, which is Figure 6 The result of the differential integrator circuit shown (i.e., the average charge per pulse). Figure 6 The differential integrator circuit 700 is an example of a circuit used to integrate the current measured over time, quantify the delivered charge, and thus determine the charge output on the treatment pulse. The number of pulses in the treatment is T*f.

[0058] like Figure 6 As shown, MON_CURRENT 760 is the result of the differential integrator circuit 700. An analog-to-digital converter (“ADC”) 710 is used to quantize the voltage into a representation of the amount of charge delivered. A Kelvin connection 740 is used to measure the voltage between electrodes A 720 and B 730. Electrodes A 720 and B 730 are connected to a header 750. A reference voltage VREF 770 is included to keep the measurement results within range.

[0059] In some examples, the analog-to-digital converter 710 is an internal feature of the controller 270. In other examples, the analog-to-digital converter 710 is an external component that passes its digital output value to the digital input port on the controller 270.

[0060] At points 504 and 506, each pulse is sampled. In one example, the functions at 504 and 506 are performed for 10 seconds at a pulse rate of 20 Hz, which can be considered a complete treatment cycle. The result of sampling phase 500 is Q. target The target pulse charge.

[0061] Figure 7 This is based on an example table showing the number of pulses per treatment measured for two parameters: frequency and duration. Frequency is shown on the Y-axis and duration on the X-axis. Generally, the adaptive protocol performs better with more pulses. One example uses a minimum of 100 pulses to provide reliable convergence for charge data feedback, but fewer pulses can be used in other examples. Reference Figure 7 A frequency setting of 20Hz and a duration of 10 seconds produced 200 pulses.

[0062] In one example, when the user acquires the results of the acquisition phase 500 and the reference charge Q, target Reproducibility phase 520 begins when another follow-up treatment is initiated. For example, as described above, a complete treatment cycle may take 10 seconds. After a two-hour pause, as shown in waiting period 522, the user can then initiate another treatment. During this phase, the adaptive protocol attempts to deliver Q to each follow-up treatment. target The functionality of the reproduction phase 520 is necessary because conditions such as the user's body impedance due to sweat or air humidity may have changed during the waiting period 522. The differential integrator is sampled at the end of each pulse during treatment. At this point, the next treatment begins, and the differential integrator is sampled for each pulse at 524 to correlate with the acquisition phase Q. target Comparisons are made. Pulse sampling includes measuring the pulse output based on the total charge. Figure 6 The voltage output of the integrator (referred to as Mon_Current 760) has a direct linear relationship with the delivered charge and provides a reading of how much charge is leaving the device and entering the user. At 526, each individual pulse is compared with the charge value (i.e., the target charge) determined in the acquisition phase 500, and the next pulse will adjust in the direction of the differential.

[0063] NUM_PULSES=(T*f)

[0064] After each pulse, the observed charge Q pulse (i) Compare with the expected charge for each pulse.

[0065] Q pulse (i)>Q target / NUM_PULSES?

[0066] Then, for subsequent pulses, adjust the output charge or "V" at 528 (decrease) or 530 (increase) using the following formula. BOOS Modify "T":

[0067] dV(i)=G[Q target / NUM_PULSES-Q pulse (i)]

[0068] Where G is an empirically determined voltage adjustment factor. The process continues at 532 until the last pulse.

[0069] Safety features ensure V BOOST It will never be increased by more than 10%. If more charge is needed, the repetition rate or duration can be increased.

[0070] In one example, the boost circuit uses dedicated circuitry to servo the boost voltage. This circuitry processes voltage and / or current measurements to control the PWM duty cycle of the boost circuit's switches. The system controller can set the voltage by adjusting the gain of the feedback loop in the boost circuit. This is accomplished via a digital potentiometer or other analog-to-digital circuitry.

[0071] In one example, generally, during the acquisition phase 500, the current is sampled for each pulse to establish a target charge for reproduction. Then, during the reproduction phase 520, the voltage is adjusted via a digital potentiometer (referred to herein as a “potentiometer (Pot)”) to achieve the established target charge.

[0072] The digital potentiometer is calibrated with the actual voltage upon startup. A table is generated using the sampled voltage for each tap (wiper) value. The table is also pre-calculated to store the potentiometer tap increments required for the 1V and 5V output difference (delta) at each potentiometer level. This allows for rapid reference voltage adjustment during the reproduction phase. Due to battery levels, this table may require periodic recalibration.

[0073] In one example, during acquisition phase 500, the dataset = 100 pulses, and each pulse is sampled, with the average value used as the target_charge for reproduction phase 520. Generally, fewer pulses provide weaker data samples to serve as the basis for reproduction phase 520.

[0074] In one example, during acquisition phase 500, the maximum dataset is 1000 pulses. This maximum value is used to avoid overflow of the 32-bit integer when accumulating the total number of samples. Furthermore, in this example, 1000 pulses is a sufficiently large dataset, and collecting more pulses may not be necessary.

[0075] In the example above, target_charge will be calculated after 1000 pulses. Additional pulses exceeding 1000 during the acquisition phase do not contribute to the calculation of the target charge. In other examples, the maximum dataset exceeds 1000 pulses when longer treatment cycles are desired.

[0076] In one example, the first 3-4 pulses are typically higher than the remaining pulses, therefore these first 3-4 pulses are not used in acquisition phase 500. This is also considered in reproduction phase 520. Using these excessively high values ​​would result in the target charge being set too high and overstimulating subsequent treatments in reproduction phase 520. In other examples, more advanced averaging algorithms can be applied to eliminate high and low values.

[0077] In the example, there might be safety concerns regarding automatically increasing the voltage. For instance, if the connection between the device and the user's skin is poor, the voltage might automatically adjust to its maximum value at 530. Then, for example, the impedance might decrease due to the user pressing the device firmly, potentially causing a sudden surge in current. Therefore, in one example, if the sample is 500mV or higher than the target, it will immediately adjust to the minimum voltage. The example then remains at the reproduction phase 520 and should adjust back to the target current / charge level. In another example, a maximum voltage increase (e.g., 10V) is set for a single treatment. Achieving the established target_charge does not require more than this. In another example, for V... BOOST A maximum value is set (e.g., 80V).

[0078] In various examples, stability is desired during the reproduction phase 520. In one example, this is achieved by gradually adjusting the voltage. However, relatively large step sizes can lead to oscillations or overstimulation. Therefore, voltage adjustments can be made in smaller steps. The step size can be based on the difference (delta) between the target current and the sample current, as well as the actual voltage (V). BOOSTVoltage level. This facilitates rapid and stable / smooth convergence to the target charge, and allows for more gradual adjustments at lower voltages for more sensitive users.

[0079] The following are conditions that can be evaluated to determine the adjustment step size.

[0080] delta-mon_current=abs(sample_mon_current-target_charge)

[0081] For increasing the adjustment, if delta_mon_current > 500mv and V BOOST If the voltage is >20V, then the step size is 5V.

[0082] (For reducing the adjustment, a difference of 500mV will trigger an emergency reduction to the minimum voltage.)

[0083] If delta_mon_current > 200mv, then step size = 1V

[0084] If delta_mon_current > 100mv and delta_mon_current > 5% * sample_mon_current, then step size = 1V

[0085] In other examples, a new treatment begins with a voltage lower than the target voltage, buffered by approximately 10%. The impedance is unknown at the start of treatment. These examples save the target_voltage in use at the end of treatment. If the user does not manually adjust the intensity parameters, a new treatment will begin with the saved target_voltage, buffered by 10%. This quickly achieves the target current with the 10% buffer, thus avoiding potential overstimulation when the impedance has been reduced. This also compensates for the typically higher first 3-4 pulses.

[0086] As disclosed, an initial charge level is applied, and then automatically adjusted based on feedback of the applied current amount. The charge amount can vary upward or downward during application. Therefore, instead of setting and then applying a fixed voltage level throughout the treatment cycle, the present invention measures the amount of charge being input to the user and adjusts accordingly throughout the treatment to maintain a target charge level suitable for the current environment.

[0087] The adaptive circuit described above provides a means to monitor the charge transmitted to the user's tissue via electrodes and adjust the intensity and duration of the transmitted charge to adapt to impedance changes through the electrode-skin interface and through the user's tissue, such that the field strength at the target nerve is within the range required to overcome the nerve action potential at that location and activate the nerve impulse. These impedance changes may be due to environmental changes, such as moisture or dryness of the skin or underlying tissue; or due to applied lotion; or due to tissue changes, such as dry skin; or due to changes in the placement of the device on the user's skin, such as due to removing the patch and reapplying the patch at a different location or orientation relative to the target nerve; or due to a combination of the above and other factors.

[0088] The combinational circuitry and circuit control disclosed herein generate a repeatable charge for subsequent use. Voltage boosting conserves battery power by generating voltage on demand. The result is an efficient and compact electronic package suitable for mounting on or within fabric or similar materials to adhere to the dermis, thereby allowing electrodes to be placed near selected nerves to be activated.

[0089] In one example, a voltage multiplier circuit using two diode stages was added. Figure 2 The boost circuit 200 doubles or reduces the voltage stress on FET 242 to double the high-voltage output. When FET 242 is turned on, the voltage doubler circuit accumulates charge in the transfer capacitor and adds voltage to the output of boost circuit 200 when FET 242 is turned off. The diode conducts only in the positive phase, thus doubling the voltage.

[0090] Figure 8 The illustration shows a method that can be used to replace [something] in the example invention. Figure 2 The boost converter circuit 200 includes the boost converter circuit 210 and the boost converter circuit 810. The boost converter circuit 810 includes three diode stages, with diodes 826 and 828 and capacitors 822 and 824 added.

[0091] Oscillator timing

[0092] In this example invention, controller 270 includes a real-time clock (“RTC”) circuit for measuring time intervals, including the time between activation pulses and the width of the activation pulses. The RTC circuit operates continuously on controller 270 to continuously track in real time. However, this continuous operation constantly drains the battery.

[0093] In other example inventions, the RTC circuitry is not used and is set to a non-operating mode by firmware in controller 270. The firmware uses an on-chip oscillator with a known frequency to set a timer, and thus can measure time intervals. When patch 100 is connected to the key fob or smart controller, the firmware resets the counter to zero. The zeroing time becomes the initial time for subsequent activation events. The firmware adjusts the counter value whenever the time on the timer, as measured by the on-chip oscillator, has elapsed. The firmware can report the counter value to the key fob or smart controller, or both. The key fob and smart controller use a real-time clock in their own controller to calculate the real-time value of the activation time by adding a value proportional to the counter value and the activation period to the real-time clock value. This allows the firmware to avoid using the on-chip real-time clock, thereby saving power and extending battery life in patch 100, and further allows the key fob or smart controller to calculate real-time markers for patch 100 activation. These markers are useful for analyzing the operation of patch 100. The on-chip oscillator operates continuously but consumes significantly less power than the on-chip real-time clock. In the example invention, controller 270 includes a 32.768kHz + / -250ppm RC oscillator. When divided by 2... 15 A one-second interval is generated at any time.

[0094] Current measurement of charge delivery

[0095] As disclosed above, in the example invention, the charge delivered to the user by the patch 100 is using... Figure 6 The differential integrator circuit 700 is used to determine this.

[0096] Figure 9 The illustration shows a charge monitoring circuit 900 for determining the charge delivered to a user by patch 100, as in other example inventions. Circuit 900 measures the battery current to the high-voltage boost circuit. Charge monitoring circuit 900 includes a current-measuring resistor 1142 for providing the controller 270 with a measurement of the current flowing into the load as load current 1120 over time. The amount of charge required to recharge the boost regulator (e.g., the amount of charge required to recharge the boost regulator) is also shown. Figure 8 As shown, the high voltage (used to generate a high voltage for the electrodes) is used to measure how much charge is transferred to the user at electrode 320. Controller 270 acquires a measured voltage MON_IBAT 1140 proportional to the current input of the boost regulator as input, and repeats this acquisition for each application pulse. Controller 270 sums the charge calculated from each MON_IBAT 1140 measurement to determine the total charge passing through current measuring resistor 1142. In a similar manner, controller 270 measures the voltage at battery 260 as V. BAT1110. Controller 270 uses the MON_VBAT 1130 value to check whether battery 260 continues to output sufficient voltage. Resistors 1132 and 1144 reduce noise in the measurement.

[0097] and Figure 6 Compared to the differential integrator circuit 700, the current monitoring circuit 900 uses fewer components, does not require precision components, and uses less space on the corresponding printed circuit board (“PCB”) (e.g., a rigid substrate such as FR-4, or a flexible substrate such as polyimide).

[0098] Monitoring V BOOST

[0099] The impedance of the connection from one electrode on patch 100 to the user, then through the user's tissue, and back to the opposite electrode on patch 100 can vary due to factors such as ambient humidity or skin dryness. As impedance changes, V BOOST The required voltage will vary to provide a charge value selected by the user or set by default to stimulate the target nerve. In an open-loop design, the same voltage is applied to each stimulus. BOOST This could lead to a decrease or increase in the amount of charge delivered to the user, which would affect the effectiveness of the stimulation. It could also affect user comfort, as the skin will perceive the stimulation pulse differently depending on changes in impedance.

[0100] As a comparison Figure 10 The illustration shows a closed-loop circuit 1300 used in the example invention for measuring the charge applied to a user via an electrode voltage measurement. In the closed-loop circuit 1300, for V... BOOST Sampling is performed, and the delivered charge is calculated for each stimulus pulse delivered to the user.

[0101] Circuit 1300 includes a voltage divider 1310, which includes two resistors R1 and R2. The voltage divider 1310 is used to scale the treatment pulse voltage 1320 to a lower range MON_VOLTAGE 1330 for sampling by the ADC 1325. By repeatedly sampling the voltage at MON_VOLTAGE 1330 during the duration of an applied stimulation pulse, the voltage waveform of the pulse (i.e., the amount of voltage applied to the user for a single pulse that decays exponentially during the pulse) can be obtained.

[0102] Voltage divider 1310 is connected in parallel with the user anatomy, represented as RL 1340 in this simplified resistance model. The human body capacitance model, as defined by the Electrostatic Discharge Association (“ESDA”), is a 100 picofarad capacitor connected in series with a 1500-ohm resistor. The pulse voltage is measured at MON_VOLTAGE 1330 and integrated over the pulse duration, then divided by the resistance of RL1340 to calculate the integral of the current, i.e., the total charge. RQ1 is the “on-resistance” of switching transistor 1312 and should be 14 ohms or less. Switching transistor 1312 will switch the high voltage VBOOST to the electrode for short time intervals, and... Figure 10 It is shown as RQ1, and its "on-resistance" is modeled. It is an open circuit when no pulse is applied.

[0103] The firmware of the patch 100 tests the value of MON_VOLTAGE 1330 when it is read by the ADC 1325 at a sampling frequency of MON_VOLTAGE 1330. In each iteration, the applied voltage is calculated based on the MON_VOLTAGE value. When the applied voltage reaches the user-selected level or the default value, the switching transistor (i.e., ...) is activated. Figure 8 The switching transistor 242 is turned on to stop applying more charge to the user, because the PWM is in V BOOST Stop when its goal is achieved. As disclosed, Figure 10 yes Figure 6 The replacement is used, and the current of each measuring electrode is determined, and then the amount of charge delivered to the user is determined. Figure 9 Measure the battery current.

[0104] Adaptive waveform for fine intensity control

[0105] The oscillator clock frequency in the example invention is selected to optimize the power consumption of the clock circuit while also providing sufficient speed for microcontroller operation and other timing circuits disclosed above.

[0106] The PWM circuit 244 modifies the pulse width by changing the count of oscillator clock cycles. Due to the limited clock frequency, it may be difficult to achieve sufficient resolution within the PWM duty cycle to create enough different intensity levels in the stimulus. This could result in the user being unable to choose between a level that is too weak and the next, stronger level that is too strong.

[0107] Therefore, in the example invention, the boost (V) BOOSTThe control is enhanced by the aforementioned level selection within the PWM duty cycle, rather than by initiating stimulation at the moment the boost ramps up to the desired voltage as read by the microcontroller's ADC, to provide greater discrimination between levels. This achieves far more intensity levels, with smaller gaps between levels compared to those limited by PWM resolution due to the much higher ADC measurement frequency. Once the desired voltage threshold is reached, feedback to the microcontroller's ADC is used to shorten the PWM activity time.

[0108] In addition to providing more levels of intensity adjustment, it conserves battery power by stopping the increased voltage output until the next pulse is needed. Some battery types perform poorly when the rate of change of the current required by the battery exceeds a certain maximum specification. Circuitry that starts by demanding current from the battery and increases the required current level at a slower rate allows the battery to perform better over several such charge cycles.

[0109] In one example, the PWM duty cycle varies from the first pulse to the last in a series of pulses used for stimulation, using a lower duty cycle pulse at the beginning of stimulation and a higher duty cycle pulse later in stimulation. The narrower pulses resulting from the lower duty cycle reduce the charging demand on the battery circuitry, causing the current demand to start more slowly compared to circuitry without duty cycle adaptation, and continuing to provide wider pulses and higher current demands through the stimulation pulse sequence in order to stay within the battery's current specifications while also increasing the stimulation energy to meet the user's needs as they adjust the intensity.

[0110] Qualified application of stimulation pulses

[0111] The energy provided by the battery for each stimulation pulse depends on the type of battery in patch 100. Battery performance varies during the application of the pulse sequence. Battery performance can be affected by temperature, humidity, battery age, and other factors. Due to this variation in battery performance, in this example invention, the treatment is adjusted most of the time, or each time, when the treatment is applied to the user.

[0112] Figure 11 and Figure 12 This is a flowchart of a treatment monitoring function invented according to an example. Figure 11The process involves "normal" treatment monitoring at 1202, beginning with the initialization of ramp intensity at 1210 and the initialization of the phase index at 1212 prior to treatment, followed by a normal application cycle at 1220. Each iteration of the cycle at 1220 applies a stimulation pulse at 1222, increments the pulse count at 1224, and then measures the pulse voltage at 1226. The amplitude of each pulse is tested according to the intensity setting at 1228. In the example invention, the intensity levels are 1-20, resulting in voltages from 4V to 85V. Pulses that do not reach the target amplitude are counted at 1230. The "good" pulse count is the number of pulses that meet the intensity level, and the "missed" pulse count is the number of pulses minus the good pulse count. When the last treatment pulse has been applied at 1240, the "missed" pulse count is compared to the "missed" pulse limit at 1250.

[0113] If in Figure 11 The number of 1250 instances where a good pulse count was not met, then... Figure 12 The "extended" treatment monitoring function 1204 is involved. If the target amplitude is not reached due to more pulses than allowed by the non-reaching pulse limit, then one or more extended treatment pulses are applied at 1260. These pulses are added to... Figure 11 The pulse count in the original treatment is adjusted to prolong the treatment time. When enough extended treatment pulses are applied at 1270 to meet the required number of pulses of intensity, the treatment is completed at 1290.

[0114] In this example invention, the target neural stimulation pulse amplitude is set by one or more of the user, firmware in patch 100, or a smart controller. To deliver at least the minimum number of pulses required for treatment, patch 100 measures the amplitude (i.e., voltage level) of each applied stimulation pulse. "Normal" treatment is delivered over a fixed time length. Each pulse that does not reach the target amplitude is not counted as one of the pulses in the minimum pulse count for treatment. After the normal treatment time has elapsed, patch 100 checks whether a sufficient number of strong pulses have met the minimum pulse count limit. If yes, then the treatment ends. If not, then... Figure 12 The function applies additional pulses to complete the treatment, thereby extending the treatment duration. If this extension exceeds the maximum treatment time at 1280, the treatment is stopped at 1290, even if the minimum number of strong pulses applied has not yet been met.

[0115] The patch 100 records the applied pulses, high-intensity pulses, treatment time, and counts of other parameters. This collected data can be transmitted to a smart controller or another data storage device for later analysis.

[0116] Firmware construction

[0117] like Figure 2 As shown, patch 100 includes control unit 1002. The feature set in control unit 1002, which provides control over the functions of patch 100, is the most common feature set across a specific set of control chips used in control unit 1002.

[0118] When firmware is designed to use a different set of features on each of the provided chips, the differences in features provided on each of the several chips that can be used to build the control unit 1002 lead to increased firmware complexity. This increased complexity results in an increase in firmware problems in the set of patches 100 built on several chips, and increases the frequency of firmware updates that need to be delivered to that set of patches 100. This increase in problems and updates limits the functionality of patches 100 in those user subsets that activate patches 100 themselves.

[0119] By using features compatible across a larger set of available chips to implement functionality in the firmware, the example invention reduces code complexity, the frequency of firmware issues, and the frequency of firmware updates.

[0120] In one example, between two different chips that can be used as alternatives to control unit 1002, one chip provides interrupt services while simultaneously performing analog-to-digital conversion in parallel with one or more peripheral devices, such as ADCs. The second chip provides both interrupt services and ADC conversion, but not simultaneously or in parallel. Therefore, the firmware for patch 100 is implemented using timer-based code instead of interrupt-based code, allowing the same firmware to be executed on either of the two chips, thus reducing the code to a single compatible implementation.

[0121] In one example, between two different chips that can be used as alternatives to control unit 1002, one chip provides support for many command types in BLE wireless communication, while the second chip only provides support for the lowest level of BLE commands. Therefore, the firmware of patch 100 is implemented using only the lowest level of BLE commands, such as single write and single read commands, thus reducing the code to a compatible implementation.

[0122] When decoding commands received as byte values ​​via the link between the smart controller or key fob and patch 100, BLE command encoding bit errors can cause problems or delays in processing functions requested by the smart controller or key fob (such as write-back or read-back), or initiating or terminating functions in patch 100. These bit errors are sometimes a result of weak signal quality between patch 100 and the smart controller or key fob. The distance between these devices varies depending on user preferences.

[0123] The patch 100 measures the received signal strength across BLE and quantifies it into a Received Signal Strength Indication (“RSSI”) binary value. The smart controller and / or key fob requests these measurements using one or more BLE commands implemented in the firmware of the patch 100 and the smart controller and / or key fob. The smart controller and / or key fob send these measurements to a computer, server, or cloud for analysis. The analysis can correlate the RSSI level with the retransmission rate of commands or data and can calculate statistics on a wide range of BLE functions within the patch 100. These statistics and correlations are used to modify the firmware and / or hardware design of the smart controller, key fob, or patch 100 to improve reliability and responsiveness.

[0124] BLE command opcodes are designed to minimize undetected bit errors when patch 100 receives a command. For each opcode with a binary mode, there is a corresponding opcode with the opposite binary mode. This avoids command opcodes that differ by only one bit.

[0125] Stacking of patches

[0126] Figure 13 The illustration shows a stacked view of patch 100 according to an example invention. The substrate 910 is a strip of fabric with adhesive on the skin-facing side. For each electrode 920, a hole 912 is cut out in the substrate. A removable paper 914 is adhered to the adhesive on the skin-facing side of the substrate 910. Two or more electrodes 920 are coupled to a printed circuit board assembly (“PCBA”) 930 via wires 922.

[0127] Electrode 920 is covered with polyimide tape A 924 to prevent short circuits from electrode 920 to PCBA 930 and to prevent electrode 930 from moving within the layers of the assembly. Each electrode 930 has a hydrogel 926 coated on its skin-facing surface. Each electrode 920 has a release layer covering the hydrogel 926. Battery clip 932 is attached to PCBA 930. Battery 936 is inserted into battery clip 932. Battery pull tab 938 is inserted into battery clip 932. PCBA 930 is wrapped in polyimide tape B 934 to restrict user contact with the electronics. Top layer 940 of fabric tape with adhesive on the PCBA-facing side is stacked on top to complete the assembly. Ankle cutout 942 is designed to be shaped like bottom layer 910 and top layer 940 to accommodate the ankle bone and help the user properly position patch 100.

[0128] Hydrogel adaptation

[0129] Variations in the viscosity and composition of the hydrogel 926 cause the substance to migrate from its original area on each electrode to a wider area, potentially reaching the skin beyond the dimensions of the patch 100. As the hydrogel migrates, its electrical properties change. The circuitry on the PCBA 930 measures the voltage applied to the skin in real time during each treatment. Adaptive circuitry calculates the charge delivered to the skin, a function of many parameters, including the conductivity of the hydrogel 926. Thus, the performance of the patch 100 is maintained, while the hydrogel portion of the device alters its properties. The adaptive circuitry adjusts charge delivery to also account for all variations in body and skin conductivity, sweat, and patch contact.

[0130] As the performance of the hydrogel 926 degrades over time, the adaptive circuitry and firmware in the PCBA 930 record the expected lifespan of a specific patch while it is powered on and on the user's skin. When patch 100 determines that the device's lifespan is nearing its end, the firmware signals a notification to the key fob or smart controller so that the user receives an indication that the patch has reached its limit.

[0131] Crimp connection from electrode to PCBA

[0132] During electrode manufacturing, each electrode 920 is coated with hydrogel 926. In some examples, when manufacturing electrode 920, wires 922 are permanently attached to both the electrode and PCBA 930, such as by soldering. The electrode plus wire plus PCBA assembly is each encapsulated in an airtight bag until they are subsequently assembled with tape and adhesive layers to form a complete patch 100. Due to the complexity of these assembly steps, the hydrogel on the electrode may be exposed to air and moisture for a period of time, which can affect the expected lifespan of the hydrogel.

[0133] In this example, electrode 920 is coated with hydrogel 926, but no wires are attached at this stage. Instead, small clips are soldered to each electrode, which does not affect the hydrogel and avoids attaching the electrodes to any larger components that would require more time on the assembly line. Each of these coated electrodes is individually heat-sealed or otherwise placed in an airtight bag. The hydrogel does not degrade while the coated electrodes are inside the airtight bag.

[0134] In the example, the wire 922 is inserted into a clip previously soldered to the electrode 920. This connection is stronger and less prone to defects compared to directly soldering or attaching the wire harness to the electrode 920. The clip and wire do not affect the hydrogel 926. Each coated electrode 920, along with its clip and attached wire, is placed in an airtight bag using heat sealing or other means. The hydrogel 926 does not degrade while the coated electrode is in the sealed bag. The coated electrodes 920 are removed from their airtight bags only immediately before they are connected to the PCBA 930.

[0135] Another benefit of separating the coating electrode 920 from the PCBA 930 as two distinct sub-assemblies until they are incorporated into the complete patch panel 100 is that defective coating electrodes or those that have expired due to prolonged shelf life can be discarded without the expense of discarding the attached PCBA. The shelf life of the more expensive PCBA is independent of the coating electrode's shelf life. The inventory of these two sub-assemblies can be stored, inspected, and managed independently. This reduces the overall manufacturing cost of the patch panel 100 equipment without compromising its performance.

[0136] Die cut fabric strap

[0137] In some examples, a solid layer of fabric tape is used to place the bottom layer 910 as the layer above the electrode 920. Therefore, the total thickness of the patch 100 is partly determined by the thickness of the fabric tape above the electrode 920. Furthermore, in order to securely place the electrode 920 on the fabric tape layer, the paper cover on the fabric tape must be pulled back to expose the adhesive coating. This results in a degradation of the adhesive properties of the tape.

[0138] In the example of patch 100, the bottom layer 910 fabric strip is cut to create holes 912 for each electrode 920 according to the defined dimensions of those components. Each electrode 920 is placed in the corresponding hole, without adding thickness to the top of the fabric strip layer. Since it is not necessary to pull back the paper cover to mount the electrode 920 to the fabric strip, the adhesiveness of the fabric strip is unaffected. Holes can be cut with a die to produce precise edges without the possibility of tearing or fibers interfering with the electrode 920.

[0139] Compliance with ankle bone contour

[0140] In some examples, patch 100 has a rectangular shape. This allows the PCBA 930, battery 936, and electrode 920 to be fitted between the fabric and adhesive underlayer 910 and top layer 940, and to be adhered to the skin by the user, then peeled off and discarded after use. In some examples, patch 100 has a shape that conforms to the contour of the location where it will be adhered to the skin. The reference point for correctly positioning patch 100 is the ankle, or in some examples, the ankle bone. Therefore, patch 100 has an ankle bone cutout 942 along the vertical side, which accommodates the ankle bone when patch 100 is placed close to it.

[0141] In some examples, the cutout 942 is designed into the patch 100 only on one side, so that the battery 936, PCBA 930, and electrode 920 are properly aligned on either the left or right ankle. Two types of patches 100 can then be provided—one for the left ankle with the cutout 942 on the first vertical side, and another for the right ankle with the cutout 942 on the second vertical side.

[0142] In some examples, cutouts 942 are designed into patch 100 on both vertical sides, allowing the battery 936, PCBA 930, and electrode 920 to be properly aligned on either the left or right ankle. Patch 100 may then be supplied in only one type.

[0143] Battery and battery pull tab

[0144] The patch 100 includes a battery 936, which is surrounded by a battery clip 932 and assembled onto a PCBA 930. During manufacturing, the battery 936 is inserted into the battery clip 932 to secure it and prevent it from falling out. In addition to the battery itself, a battery pull tab 938 is positioned between a contact of the battery 936 and a corresponding contact in the battery clip 932. The battery pull tab 938 prevents the battery 936 and the battery clip 932 from being electrically connected at that contact point until the battery pull tab 938 is removed. When in place, an open circuit exists, preventing the patch 100 from being activated and from consuming power until the battery pull tab 938 is removed.

[0145] In some examples, the battery pull tab 938 is designed to be removed by pulling it out in the opposite direction to the direction in which the battery 936 is inserted into the battery clip 932. This pulling action may cause the battery itself to move because it will be pulled toward the opening side of the battery clip 932. This battery movement may cause the patch 100 to stop operating or never activate.

[0146] In one example, the battery pull tab 938 and battery clip 932 are designed such that the battery pull tab 938 is pulled out in the same direction as the battery 936 is pushed into the battery clip 932. Therefore, the force used to pull the battery pull tab 938 out of the patch 100 is only used to make the battery 936 more secure in its battery clip 932. This reduces the chance of unintentional movement of the battery 936 and its impact on the activation or operation of the patch 100.

[0147] Electrode release film

[0148] Each electrode 920 in the assembled patch 100 is covered with a polyethylene terephthalate (“PET”) silicone-coated release film 926. When the patch 100 is applied to the skin, the release film is pulled off by the user. In some examples, the PET silicone-coated release film 926 is transparent. This can lead to user confusion when the user may not be able to determine whether the tape has been removed. Applying the patch 100 to the skin with any electrode 920 still covered by tape will render the patch 100 ineffective. This ineffectiveness may not be noticeable until the first use of the patch 100. If the applied patch 100 is found to be ineffective when the user experiences urinary urgency, the user may have difficulty urinating properly or removing the patch 100, peeling the tape off the electrodes, or applying a new patch 100 and suppressing the urinary urgency with a re-applied or new device.

[0149] In the example, the PET silicone cover release film 926 covering the electrode 920 is chosen to be a color that is easily visible to the user, making it easy for the user to determine whether the tape has been removed.

[0150] The example uses a circuit system and firmware to stimulate the electrode circuitry with short, low-energy pulses or pulse sequences when patch 100 is initially activated. If patch 100 is activated before being applied to the skin, the electrode readiness test will fail. In this case, the electrode readiness test is repeated repeatedly according to a timer in the firmware or hardware until either all timers expire or the test passes. The test passes when patch 100 exhibits circuitry performance suitable for its design. The test fails when patch 100 is not properly prepared, such as by not removing the electrode film or by not being applied to the skin when all timers expire. When the electrode readiness test fails, patch 100 signals a notification to a key fob or smart controller, which in turn notifies the user. The electrode readiness test is implemented in a way that may be imperceptible to the user and minimizes battery power consumption during testing.

[0151] Removable paper

[0152] In some examples, removable paper 914 covers the adhesive side of the base layer 910. The removable paper 914 can be in multiple sections, each of which is pulled apart by the user when the patch 100 is applied to the skin. These removable papers can supplement the sheet covering the PET film 926 of each electrode 920. Therefore, in the example, the user must remove all these sheets to expose the full adhesive surface for fixation to the skin.

[0153] In the example, the bottom layer 910 is a single sheet with one removable paper 914. The user removes all removable papers in one action. In the example, the bottom layer 910 may be two or more sheets with two or more removable papers 914. The user removes all removable papers. In the example, each removable paper 914 is designed with a pull tab so that the user can pull the removable paper from the bottom layer in a direction perpendicular to the long axis of the patch 100. This movement reduces the forces exerted on the internal components of the assembled patch 100.

[0154] In the example, removable paper 914 covers the substrate 910 and all PET film portions 926. An adhesive attaches the top surface of the removable paper to the skin-facing surface of the polyimide tape A, allowing the user to pull the removable paper from the substrate and remove the PET film from the electrode 920 in one action.

[0155] The patch 100 can also be made more comfortable by adding materials, such as cushioning materials that can buffer electrodes and electronic components, between the top and bottom layers. In at least a portion of the patch 100, the cushioning material may be disposed below the bottom layer and above the top layer. The cushioning material may include cellulose fibers (e.g., wood pulp fibers), other natural fibers, synthetic fibers, woven or nonwoven sheets, loosely woven meshes or other stable structures, superabsorbent materials, foams, adhesive materials, and combinations thereof.

[0156] Hydrogel overlap with electrode edges

[0157] In some examples, each electrode 920 is covered with hydrogel 926, which conforms to the size of the electrode 920 such that when the patch 100 is applied to the skin, the edge of the electrode 920 is exposed to the user's skin. During the application of the patch 100 to the skin, this edge may abrade or cut the user's skin.

[0158] In some examples, the hydrogel 926 is sized to overlap the edge of the electrode 920. The hydrogel 926 is placed on the electrode 920 with the placement accuracy used in manufacturing, such that the edge of the electrode 920 is always covered by the hydrogel 926. This prevents the edge of the electrode 920 from contacting the user's skin. Therefore, the risk of the electrode 920 abrading or cutting the user's skin is eliminated.

[0159] Figure 14 The illustration shows a stacked view of the patch 100 according to the exemplary invention assembled onto a substrate 950. A battery 936 is attached to the substrate 950 directly or via battery clips and connected to electronic devices using two or more conductive paths plated on the substrate 950. Electrodes 920 are connected to voltage and ground using through-holes 942, thereby forming an electrical path from the top surface to the bottom surface of the substrate 950. A top layer 940 is attached to the battery 936 to restrict user access to the electronic devices.

[0160] The distance between electrodes 920 can be selected to maximize the effectiveness of the electrical signal at the target nerve and / or minimize the area occupied by patch 100. Each electrode 920 can have a diameter of approximately 500 mm. 2 Up to approximately 1100mm 2 The surface area facing the body of the electrode 920. The electrode 920 can have different or the same surface area facing the body. The total surface area of ​​the electrode 920 facing the body can be less than 3,000 mm². 2 Preferably from approximately 1050 mm 2 Up to approximately 2200mm 2 More preferably from approximately 500mm 2 Up to 2200mm 2 .

[0161] The electrodes 920 may be spaced approximately 1 mm to approximately 100 mm (edge ​​to edge), preferably approximately 5 mm to approximately 80 mm, and more preferably approximately 10 mm to approximately 60 mm. The distance between the electrodes 920 can be selected to maximize the effectiveness of the electrical signal at the target nerve and / or minimize the area occupied by the nerve stimulation device. Alternatively, the patch 100 may include an electrode array. Furthermore, as... Figure 14 As shown, the electrodes 920 are spaced apart by relatively narrow isthmuses 925. The isthmuses 925 provide separation of the electrodes 920 to enhance performance and provide enhanced wearing comfort and reduced wear during prolonged use of the patch 100, especially when the patch 100 is placed on the ankle. Furthermore, the isthmuses 925 reduce stress and lead breakage between the circuitry and the battery or other components.

[0162] Matrix pattern in electrode

[0163] Figure 15 The illustrations depict solid and patterned electrodes used in different examples of patch 100. In the examples, each of the two electrodes 920 is electroplated onto the substrate layer as a continuous region, as shown. Figure 14 and Figure 15 As shown in A.

[0164] In one example, each of the two electrodes 920 is electroplated with a matrix pattern, such as Figure 15 As shown in B, the surface of each electrode is planar. There is no ripple effect seen when using continuous plating areas, and the electrodes are laid flat relative to the user's skin. Each element of the matrix is ​​connected to a common electrical node driven by an activation voltage, such that the activation voltage is simultaneously driven to all elements of the matrix.

[0165] In one example, each of the two electrodes 920 is electroplated into a stripe pattern, such as...Figure 15 As shown in C, the surface of each electrode is planar. Each element of the stripe pattern is connected to a common electrical node driven by an activation voltage, such that the activation voltage is simultaneously driven to all elements of the matrix. The common electrical node can be in a PCB layer separate from the outer plating layer, or it can be formed by connecting stripes around its perimeter or by connecting stripes from stripe to stripe at the midpoint.

[0166] In one example, a printed circuit board assembly (“PCBA”) 930 (e.g., using one or both sides of a PCB, whether rigid or flexible, for electroplating conductive paths and mounting electronic components) is assembled onto a flexible substrate instead of a rigid substrate, such as... Figure 14 As shown, this results in the ripples seen when no rigid substrate is used, and the PCBA is laid flat relative to the user's skin.

[0167] The total area of ​​the electrodes in the form of a matrix or stripes is calculated to provide sufficient coverage on the user's skin to allow for variations in electrode placement at the target location of neural activation, such that even if patch 100 is placed off-center from the optimal position, the electrodes extend across the target area sufficiently to deliver effective stimulation.

[0168] In this example invention, a layer of hydrogel 926 is coated on each electrode 920. While the electrodes 920 are electroplated into a matrix, stripes, or similar pattern, the hydrogel is a continuous area across each of the two electrodes. This continuous conductive surface distributes the applied pulsed voltage across the entire skin area to avoid disturbing the skin's surface.

[0169] Protection of circuit components

[0170] The hydrogel 926 layer is applied to the electrode side of PCBA 930. Through-holes are used to connect from the top surface of the PCB to the bottom surface, thereby providing electrical connections to one or more components, such as a SOC 1000. During the use of the patch 100, the hydrogel can migrate to the top surface of the PCB through one or more of the through-holes. This conductive migrating material may interfere with the performance of one or more electrical components on the top surface of the PCB, such as causing ground shorts or other voltage shorts on one or more pins of such components (e.g., SOC 1000).

[0171] The PCB is manufactured with a layer covering one or more through-holes, which is then adhered to the bottom side of the PCB. After the cover layer is applied over the through-holes, hydrogel 926 is applied to the bottom side of the PCB. The cover layer prevents hydrogel or other contaminants (such as water) from entering and / or penetrating and / or migrating through the through-holes, thus forming a permanent barrier that allows the functionality of patch 100 to be maintained through repeated use by the user. This cover layer also prevents intrusion and migration from manufacturing to the user's first use, thereby ensuring the shelf life of patch 100.

[0172] Hydrogel impedance

[0173] The electrical power required to perform stimulation is related to the applied voltage and the impedance seen by electrode 920 through hydrogel 926 and the user's skin. When the hydrogel has higher impedance, more electrical power is required to perform stimulation. Utilizing a fixed amount of electrical power available from battery 936 in patch 100, this energy per stimulation limits the number of stimulations that can be performed.

[0174] In one example, a hydrogel 926 with lower impedance was chosen to allow for less energy consumption in the circuit and more stimulation per patch 100 using battery 936. The impedance of the hydrogel can be minimized by one or more of the following methods: reducing the thickness of the hydrogel coating, changing the material composition, and increasing the size of the hydrogel coated on electrode 920, or even extending it beyond the electrode boundary to the bottom surface of PCBA 930.

[0175] Several examples are illustrated and / or described herein. However, it will be appreciated that the above teachings cover modifications and variations of the disclosed examples without departing from the spirit and intended scope of the invention, and such modifications and variations are within the scope of the appended claims.

Claims

1. A topical nerve activation patch, comprising: a substrate; a dermal-adhesive bottom surface of the substrate, including an adhesive and adapted to contact a dermis of a user; a top outer surface of the substrate, generally parallel to the bottom surface; a plurality of electrodes positioned on the patch proximate the bottom surface and below the top outer surface and coupled to the substrate; a power source; and electronic circuitry embedded in the patch and below the top outer surface and coupled to the substrate, the electronic circuitry configured to generate an output voltage applied to the electrodes, the electronic circuitry comprising: a controller configured to generate a therapy comprising a plurality of activation pulses forming the output voltage, the controller comprising a first real-time clock and an oscillator having a known frequency, the therapy comprising electrical stimulation applied to the user via the electrodes; a charge measurement circuit configured to measure an amount of charge applied to the user from the electrical stimulation; and a communication link configured to communicate with a remote activation device, the remote activation device comprising a second real-time clock; the controller configured to generate the activation pulses comprising: setting a timer using the oscillator; adjusting a counter value each time the timer elapses; sending the counter value to the remote activation device, the second real-time clock adapted to determine an activation time of an activation pulse by adding a value proportional to the counter value and an activation period to a second real-time clock value, and sending the activation time to the controller.

2. The topical nerve activation patch of claim 1, the controller configured to generate activation pulses without using the first real-time clock.

3. The topical nerve activation patch of claim 1, the electronic circuitry further comprising a pulse width modulation (PWM) circuit, the pulse width modulation (PWM) circuit configured to modify a width of one or more of the plurality of activation pulses during a PWM duty cycle.

4. The topical nerve activation patch of claim 3, the electronic circuitry further comprising a boost circuit, the boost circuit configured to ramp up a voltage level of each of the activation pulses to a desired level.

5. The topical nerve activation patch of claim 4, the controller configured to stop the boost circuit output between activation pulses until the next pulse is needed.

6. The topical nerve activation patch of claim 5, the controller configured to vary the PWM duty cycle during the plurality of activation pulses such that a lower PWM duty cycle is used at a beginning of the electrical stimulation to form a relatively narrow pulse, and a higher PWM duty cycle is used at an end of the electrical stimulation to form a relatively wider pulse.

7. The topical nerve activation patch of claim 1, the therapy comprising a pulse count, the controller configured to determine a count of a number of activation pulses reaching a predefined intensity setting during generation of the plurality of activation pulses, and to generate an additional pulse to add to the pulse count when the count does not exceed a predefined number. ​ 8. The local nerve activation patch of claim 1, the remote activation device comprising a key fob or a smart phone.

9. The local nerve activation patch of claim 1, the charge measurement circuit comprising circuitry to determine an amount of charge needed to recharge a boost regulator coupled to the electrodes.

10. The local nerve activation patch of claim 1, the charge measurement circuit comprising circuitry to repeatedly sample a voltage of the electrodes during a duration of one applied stimulation pulse.

11. The local nerve activation patch of claim 1, at least one pair of electrodes of the plurality of electrodes separated by an isthmus.

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