Electrical stimulation system with a deformable stimulator and related method

Abstract

The present invention provides a wirelessly powered electrical stimulation system. In one embodiment, the system comprises: a) a power transmitter comprising a wearable transmitting coil for wireless power transmission and a portable control circuit; and b) a wireless electrical stimulator comprising a power management module and a pulse stimulation module configured to apply electrical stimulation to a target tissue. In one embodiment, the wireless electrical stimulator further comprises a sensing module configured to monitor the motility or electrophysiological signals of the target tissue. In one embodiment, the wireless electrical stimulator is made of a flexible or pliable material. The wireless electrical stimulator is configured to be delivered through a natural orifice without open surgery. Related minimally invasive implantation methods are also provided.

Description

Technical Field

[0001] The present invention generally relates to a wireless power supply medical device for minimally invasive electrical stimulation therapy to restore the normal function of typical muscle groups such as the digestive tract.

Background Art

[0002] Functional electrical stimulation (FES), a method of using electrical stimulation to restore the degenerated function of typical muscle groups, is widely used clinically. For example, it helps patients with spinal cord injuries regain some normal functions such as grasping and walking. Various systems, sensors, and algorithms have been investigated to improve performance. Transcutaneous electrical stimulation is a non-invasive method, but high voltage or high current is required to apply effective stimulation across the entire skin. In contrast, implanted stimulation devices directly apply electrical pulses to control the target muscle group. However, the operating time of the device is limited by the battery capacity. Frequent battery replacement increases the risk of infection and other side effects.

[0003] Wireless power transmission is a promising solution for implanted medical devices. However, efficient power transmission through deep tissues remains difficult because electromagnetic energy is significantly attenuated by deep tissues. Furthermore, the efficiency of wireless power transmission highly depends on the orientation, position, and geometric structure of the receiving coil.

[0004] Here, a system, device, and related implantation method for wireless electrical stimulation are provided. The electrical stimulation device is powered by a wireless power transmission system, thereby extending its lifespan and eliminating the need for battery replacement and related potential risks. An endoscopic delivery method through natural pores is also disclosed as a minimally invasive delivery method. This avoids open surgery for implantation and thus reduces the risk of infection during recovery.

Summary of the Invention

[0005] Systems, apparatus, materials, and related methods for wireless electrical stimulation systems are disclosed. The system comprises an electrical stimulator having a transmitting coil for wireless power transmission and a receiving coil. The transmitting coil is located outside the body and generates an alternating magnetic field for wireless power transmission in deep tissue. The electrical stimulator comprises a receiving coil, a power management module, a pulse generator, and a pair of electrodes. Furthermore, related minimally invasive delivery methods are also provided. The electrical stimulator is delivered or implanted via a natural orifice by endoscopy without requiring open surgery.

[0006] In one embodiment, a wireless power transmission system is provided. Generally, the system comprises one or more transmitting coils with matching capacitors, a power supply, and associated control circuits. Alternating current is applied to the transmitting coils. Based on Faraday's law, the transmitting coils generate an alternating current magnetic field. The transmitting coils are also configured in different geometric shapes. In some embodiments, the transmitting coils have a solenoid shape, which generates a strong magnetic field within the region enclosed by the coils. In some embodiments, the coils are a pair of Helmholtz coils. In some embodiments, the coils are braided into a pair of solenoid coils. In some embodiments, the coils are braided into a planar pad.

[0007] In some embodiments, a direct current (DC) power supply is converted to alternating current (AC) by a full-bridge inverter. The frequency is controlled by a pulse-width modulated signal generated by a control circuit.

[0008] In some embodiments, a signal generator produces an AC voltage, and the corresponding signal is amplified by a power amplifier.

[0009] In one embodiment, a wireless electrical stimulation device is provided. A receiving coil surrounds a closed region. An AC voltage is induced in the receiving coil while an AC magnetic field is transmitted through the closed loop. The AC voltage is then converted to a DC voltage by a full-bridge rectifier. The high-amplitude and high-noise voltage is then regulated to a stable voltage by a power management module. Finally, a pulse generator produces a pulsed voltage having a typical frequency, amplitude, and pulse width.

[0010] In some embodiments, the electrical stimulator may also include a microcontroller unit (MCU) for setting these parameters.

[0011] In some embodiments, a constant current module is positioned following the pulse generator. The constant current module converts the pulse voltage into a pulse current of constant amplitude while being applied to various loads.

[0012] In some embodiments, the electrodes are manufactured in the shape of microneedles that penetrate the tissue.

[0013] In some embodiments, the power management module comprises a full-bridge rectifier and a low-dropout (LDO) linear regulator.

[0014] In some embodiments, the power management module may also include a step-down converter for more efficient power transmission.

[0015] In one embodiment, a method for delivering endoscopic devices and related applications are provided. Natural openings such as the digestive tract and urinary tract are accessible by endoscopy, thereby providing a minimally invasive method for implanting or delivering electrical stimulators.

[0016] In some embodiments, a per-oral endoscopic myotomy (POEM) technique is used to create a tunnel between the mucosal and muscular layers of the esophagus. A miniaturized electrical stimulator is then delivered to the esophagus and implanted through the tunnel. The tunnel is then sutured or closed with several endoscopic clips.

[0017] In some embodiments, the electrical stimulator is integrated onto a medical device such as a stent. It is delivered via a thin catheter through a natural orifice. After the stent is released, the electrical stimulator remains in the body.

[0018] In some embodiments, electrical stimulators are used in the gastrointestinal tract to regulate GI disorders such as irritable bowel disease, gastroesophageal reflux disease, and fecal incontinence.

[0019] In some embodiments, electrical stimulators are used in the bladder or urinary tract to manage urinary incontinence.

[0020] In some embodiments, electrical stimulators are used vaginally to treat pelvic floor muscle dysfunction. [Brief explanation of the drawing]

[0021] Non-limiting embodiments of the present invention are described by examples combined with schematic and not-to-scale drawings. In the drawings, identical or substantially identical components shown are typically represented by a single number. For clarity, not all components are referenced in all drawings, nor are all components of each embodiment of the present invention shown where illustration is not necessary for those skilled in the art to understand the invention. In the drawings,

[0022] [Figure 1A] This invention provides a method for minimally invasive implantation of a wireless electrical stimulation device, a wireless power transmitter, and a system comprising the wireless electrical stimulation device. The wireless power transmitter comprises a wearable power transmitter and a portable control panel.

[0023] [Figure 1B] A photograph of a typical prototype of a wireless electrical stimulation system on a mannequin is shown.

[0024] [Figure 2A] The 3D magnetic field generated by the power transmitter is shown.

[0025] [Figure 2B] The uniform magnetic field distribution within the power transmitter along the axial direction (X-axis) and radial direction (Y-axis) of the transmission coil is shown.

[0026] [Figure 3] A block diagram of a portable control box including a rechargeable battery, a power management circuit, a control circuit, and a matching capacitor is shown.

[0027] [Figure 4] A block diagram of an alternative design of a portable control box including a signal generator, a power amplifier, and an antenna automatic tuner is shown.

[0028] [Figure 5] A block diagram of a wireless electrical stimulation device including a receiving coil, a power management module, and a pulse stimulation module having one or more pairs of electrodes is shown.

[0029] [Figure 6A] Adjustable constant current stimulation with different load resistances is shown.

[0030] [Figure 6B] Biphasic constant current pulse stimulation with different load resistances is shown.

[0031] [Figure 7] Pulse stimulation having programmable frequency and pulse width in the present invention is shown. [Figure 7A] 10 Hz, which is a typical frequency for pulse stimulation, is shown.

[0032] [Figure 7B] This shows 20 Hz, a typical frequency for pulsed stimulation.

[0033] [Figure 7C] This shows 50 Hz, a typical frequency for pulsed stimulation.

[0034] [Figure 7D] This shows typical pulse widths ranging from 100 microseconds to 500 microseconds in response to pulsed stimulation.

[0035] [Figure 8A] A typical design of a wireless electrical stimulation device is shown, comprising a stent, an elastic coil, and a retractable pulse generator having one or more pairs of electrodes.

[0036] [Figure 8B] A photograph of a prototype elastic coil used as a receiving coil is shown.

[0037] [Figure 8C] The image shows a photograph of a stretchable pulse generator that undergoes various deformations, including twisting, bending, and stretching.

[0038] [Figure 8D] A photograph of an integrated wireless electrical stimulation device that involves stretching is shown.

[0039] [Figure 9] This image shows an X-ray of a non-invasive oral delivery method for a wireless electrical stimulation device.

[0040] [Figure 10A] The components of a delivery tool, comprising a balloon catheter, a block ring, a soft tip, a flexible shell, and a handle, are shown.

[0041] [Figure 10B] This shows a wireless electrical stimulation device integrated into a delivery tool.

[0042] [Figure 11] This paper presents an alternative design for a small, flexible wireless electrical stimulation device. [Figure 11A] This shows a top view of a wireless electrical stimulation device comprising a flexible circuit board, a printed receiving coil, electronic components, a printed antenna, a battery, and a pressure sensing module.

[0043] [Figure 11B] This shows a bottom view of a wireless electrical stimulation device comprising a circuit board, a printed receiving coil, one or more pairs of electrical stimulation electrodes, and one or more sensing electrodes.

[0044] [Figure 12A] This shows a typical design of a delivery tool with a soft tip mounted in a transparent holder. [Figure 12B] This shows a typical design of a delivery tool with a soft tip mounted in a transparent holder. [Figure 12C] This shows the assembly process for a delivery tool equipped with an endoscope.

[0045] [Figure 13] This paper demonstrates a minimally invasive oral delivery method for wireless electrical stimulation devices, which involves passing through a submucosal tunnel created by an endoscope. [Modes for carrying out the invention]

[0046] The present invention provides a system for stimulating target tissue with electrical signals. In one embodiment, the system comprises: a) a wireless power transmission module configured to operate at a resonant frequency, comprising one or more wearable transmitting coils and a portable control circuit; and b) a deformable wireless electrical stimulator positioned on a target and configured to operate at a resonant frequency, comprising at least one receiving coil, a power management module and a stimulating module, wherein the wireless power transmission module supplies power to the stimulating module and generates an electrical signal by generating an alternating magnetic field passing through at least one receiving coil, thereby inducing an alternating voltage which is converted into a stable voltage by the power management module.

[0047] In one embodiment, the portable control circuit comprises a) a rechargeable battery, a power management circuit supplying constant current and different voltages, a pulse width modulation generator, a full-bridge inverter, a metal-oxide-semiconductor field-effect transistor (MOSFET) driver, and one or more matching capacitors, or b) a rechargeable battery, a power management circuit, a signal generator, a power amplifier, and an automatic antenna tuner comprising one or more wearable transmitting coils operating at a resonant frequency.

[0048] In one embodiment, the resonant frequency is in the range of 100 kHz to 1 GHz.

[0049] In one embodiment, the electrical signal comprises a) a single-phase or two-phase voltage pulse or pulse train, or b) a single-phase or two-phase current pulse or pulse train, or c) a charge-balanced current pulse or pulse train.

[0050] In one embodiment, the electrical signal comprises one or more sets of parameters selected from the group consisting of a) a current amplitude in the range of 3mA to 15mA, b) a frequency in the range of 1Hz to 1000Hz, and c) a pulse width in the range of 100 microseconds to 200 milliseconds.

[0051] In one embodiment, the stimulation module comprises one or more electrodes for delivering electrical signals to target tissue.

[0052] In one embodiment, one or more electrodes have one or more features selected from the group consisting of a) one or more electrodes being needle-shaped, b) one or more electrodes being spaced 0.1 mm to 30 mm apart from each other, and c) one or more electrodes having a length in the range of 50 μm to 300 μm.

[0053] In one embodiment, the power management module includes a rectifier circuit for converting an AC voltage into a stable voltage, the rectifier circuit being selected from the group consisting of a) a plurality of diodes and capacitors, b) a full-bridge rectifier, c) a low-dropout linear regulator, d) a boost converter for increasing the stable voltage, and e) a buck converter for decreasing the stable voltage.

[0054] In one embodiment, a deformable wireless electrical stimulator is adapted to be positioned on a target through a natural orifice selected from the group consisting of the gastrointestinal tract, trachea, urinary tract, and vagina.

[0055] In one embodiment, the deformable radio-electrical stimulation device further comprises a microcontroller configured to perform one or more functions selected from the group consisting of a) setting parameters for electrical signals, b) controlling a stimulation module, and c) processing data for radio communication via a radio frequency protocol.

[0056] In one embodiment, a deformable wireless electrical simulator further comprises a sensing module configured to monitor motion or pressure within an object.

[0057] In one embodiment, a deformable wireless electrical stimulator further comprises one or more sensing electrodes configured to measure electrophysiological signals from a target tissue.

[0058] In one embodiment, one or more wearable transmitting coils are selected from the group consisting of a single solenoid, a planar coil, a pair of Helmholtz coils, a pair of solenoid coils braided with a single wire, and a planar coil with an additional resonator coil configured to operate at the same resonant frequency.

[0059] In one embodiment, the deformable radioelectric stimulation device further comprises a mechanical frame, and at least one receiving coil is an elastic coil braided along the mechanical frame.

[0060] In one embodiment, the deformable radioelectric stimulator is made of a material that allows the deformable radioelectric stimulator to stretch up to 50%.

[0061] In one embodiment, the materials include dielectric materials for the substrate and encapsulation, and intrinsic conductive materials for circuit tracing and contact pads, where a) the dielectric material is selected from the group consisting of polydimethylsiloxane (PDMS), polyurethane (PU), styrene-ethylenebutylene styrene (SEBS), polyimide (PI), polyethylene terephthalate (PET), and hydrogel, and b) the intrinsic conductive material is selected from the group consisting of silver nanowires, carbon nanotubes, gold nanowires, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), printed copper wire, and gallium-based liquid metals.

[0062] The present invention also provides a method for delivering the system of the present invention to target tissue. In one embodiment, the method includes a) inserting a delivery tool through an opening to a desired location, wherein the delivery tool comprises a balloon and a stent that is compressed within the delivery tool, and the stent is integrated with a deformable radioelectric stimulator; b) releasing the stent integrated with the radioelectric stimulator; and c) inflating the balloon so that the stimulator module is in contact with the target tissue.

[0063] In one embodiment, the opening is a natural ostium selected from the group consisting of the digestive tract, trachea, urinary tract, and vagina.

[0064] In one embodiment, the delivery tool further comprises a flexible shell, a soft tip, a block ring, and a balloon equipped with a flexible catheter.

[0065] In one embodiment, the method includes the steps of: a) creating a submucosal tunnel between the mucosal layer and the muscular layer using a standard endoscope; b) assembling a deformable radioelectric stimulator onto a delivery tool connected to the standard endoscope; c) inserting the deformable radioelectric stimulator into the submucosal tunnel; d) configuring the deformable radioelectric stimulator so that an electrical signal is delivered to the target tissue; and e) closing the submucosal tunnel.

[0066] In one embodiment, the delivery tool comprises a soft tip and a transparent holder configured to connect a wireless electrical stimulator to a standard endoscope.

[0067] In one embodiment, the target tissue is the muscular layer of the digestive tract, urinary tract, or reproductive system.

[0068] The present invention provides a wireless power supply electrical stimulation system. In one embodiment, the system comprises: a) a wearable transmitter comprising a transmitting coil and a control panel for wireless power transmission; and b) a wireless electrical stimulation device comprising a power management module and a pulse stimulation module. The system may also comprise a sensing module for closed-loop electrical stimulation.

[0069] In one embodiment, the control panel comprises a) a rechargeable battery, b) a power management circuit that supplies constant current and different voltages, c) a control circuit equipped with a pulse width modulation generator, d) a full-bridge inverter, e) a metal-oxide-semiconductor field-effect transistor (MOSFET) driver, and f) one or more matching capacitors.

[0070] In one embodiment, the alternative control panel design comprises a) a rechargeable battery, b) a power management module, c) a signal generator that generates AC signals, d) a power amplifier, and e) an automatic antenna tuner that matches the transmitting coil to the resonant frequency.

[0071] In one embodiment, the transmitting coil has a geometric structure that is a plane, a pair of Helmholtz coils, a single solenoid, or a pair of solenoids with a diameter ranging from 5 cm to 80 cm. In some embodiments, the transmitting coil comprises a planar transmitting coil and another planar resonant coil. Both coils operate at the same resonant frequency. The resonant coil boosts the power by amplifying the generated magnetic field strength.

[0072] In one embodiment, the wearable transmitter generates a magnetic field at a frequency in the range of 100 kHz to 100 MHz.

[0073] In one embodiment, the wireless electrical stimulation device further comprises a receiving coil, one or more pairs of electrodes, or a microcontroller for parameter setting and wireless communication.

[0074] In one embodiment, the power management module includes a rectifier circuit that converts alternating current to direct current and a voltage regulator that supplies a stable voltage.

[0075] In one embodiment, the pulse generator module comprises a pulse generator for generating current pulse signals or voltage pulse signals having programmable amplitude, frequency, and pulse width.

[0076] In one embodiment, the pulse generator generates a current pulse signal or a voltage pulse signal at a frequency in the range of 1 Hz to 1 kHz.

[0077] In one embodiment, the pulse generator generates a current with an amplitude in the range of 3mA to 15mA.

[0078] In one embodiment, the pulse generator generates a current pulse signal or a voltage pulse signal with a pulse width in the range of 100 microseconds to 200 milliseconds.

[0079] In one embodiment, the pulse generator generates a charge-balanced current pulse signal to avoid tissue damage and electrode corrosion.

[0080] In one embodiment, the receiving coil includes a ferrite core to improve wireless power transmission efficiency.

[0081] In one embodiment, each pair or more of electrodes is a needle-shaped electrode for applying electrical stimulation through tissue.

[0082] In one embodiment, one or more pairs of electrodes are spaced 0.1 mm to 30 mm apart.

[0083] In one embodiment, one or more pairs of electrodes have lengths ranging from 50 μm to 300 μm.

[0084] In one embodiment, one or more pairs of electrodes have a shape selected from the group consisting of cones, prisms, or spikes.

[0085] In one embodiment, the wireless electrical stimulation device comprises a substrate or encapsulation made from one or more dielectric materials selected from the group consisting of polydimethylsiloxane (PDMS), styreneethylenebutylenestyrene (SEBS), polyurethane (PU), polyimide (PI), and hydrogel.

[0086] In one embodiment, the wireless electrical stimulation device comprises circuit traces and contact pads made from one or more intrinsic conductive materials selected from the group consisting of silver nanowires, carbon nanotubes, gold nanowires, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), or liquid metals.

[0087] The present invention provides an endoscopic delivery method for a wirelessly powered electrical stimulation system for minimally invasive electrical stimulation therapy in a natural orifice, the wirelessly powered electrical stimulation system further comprising one or more pairs of electrodes. In one embodiment, the method includes a) inserting a delivery instrument through a natural orifice, the delivery instrument comprising a balloon and a stent compressed within the delivery instrument, the stent being integrated with a wireless electrical stimulation device; b) releasing the stent integrated with the wireless electrical stimulation device; and c) inserting one or more pairs of electrodes into muscle tissue by inflating the balloon.

[0088] In one embodiment, the natural opening includes the digestive tract, trachea, urinary tract, or vagina.

[0089] In one embodiment, the delivery tool comprises a flexible shell, a soft tip for safely interacting with tissue, a block ring, a balloon catheter for inserting an electrode through tissue, and a handle.

[0090] In one embodiment, regarding a delivery method for another endoscopic examination of the present invention, the delivery method includes the following steps: i) incising the gastrointestinal mucosa by endoscopy to create a submucosal tunnel between the gastrointestinal mucosal layer and the gastrointestinal muscular layer; ii) embedding a wireless stimulator in the tunnel; and iii) closing the tunnel with several endoscopic clips.

[0091] The present invention will be better understood by referring to the details of the experiments described below, but those skilled in the art will readily understand that the specific experiments described are for illustrative purposes only and do not limit the present invention as described herein, which are defined by the subsequent claims.

[0092] The present invention provides a wireless electrical stimulation system for long-term in vivo electrical stimulation therapy. Referring to Figure 1A, the present invention comprises two components: a wearable transmitter 110 with a portable control panel 120 for wireless power transmission, and a wireless electrical stimulator 100 for applying pulse signals. Alternating current flows through the transmitting coil 110, which generates an alternating current magnetic field. However, the magnetic field strength rapidly attenuates as the distance increases. Furthermore, electromagnetic energy is also attenuated by tissue. Therefore, a transmitting coil 110 with a reasonable design is important for wireless power transmission in deep tissues. The geometric structure of the transmitting coil 110 greatly affects wireless power transmission. [Examples]

[0093] In some embodiments, the transmitting coil 110 is a single solenoid that generates a strong magnetic field near the central region within the coil. The motion or orientation of the receiver may inadvertently induce a higher voltage, which can lead to safety issues. In some embodiments, the transmitting coil 110 is a pair of Helmholtz coils that generate a uniform magnetic field within the coil's region. However, its magnetic intensity is weaker than that of a single solenoid coil. In some embodiments, the transmitting coil 110 is a pair of solenoid coils braided with a single wire. This generates a uniform and relatively strong magnetic field within the coil. In some embodiments, the transmitting coil 110 has a diameter ranging from 30 cm to 80 cm to accommodate various body shapes of different individuals. In some embodiments, the wearable transmitting coil 110 is manufactured in the shape of an overall. Referring to Figure 1B, the photograph shows a typical design of the transmitting coil 110 on a human body model. Referring to Figures 2a and 2b, the wearable transmitting coil 110 generates a uniform magnetic field within the transmitting coil 110 to power a deep tissue implant.

[0094] The implantable medical device 100 is positioned within the area of ​​the transmitting coil 110. Based on Faraday's law, the receiving coil 102 of the electrical stimulator 100 induces an alternating voltage having the same frequency as the magnetic field. Furthermore, the amplitude of the induced voltage is related to the magnetic field strength and the loop area surrounded by the receiving coil 102. In some embodiments, the receiving coil 102 has a ferrite core, which increases its permeability and, consequently, increases the received voltage. In some embodiments, the receiving coil 102 is configured in three directions and in parallel to compensate for efficiency losses due to angular mismatch. [Examples]

[0095] The transmitting coil 110 is driven by an alternating current having a typical frequency that mainly depends on the geometric structure of the transmitting coil. Referring to Figure 3, the portable control panel 120 comprises a rechargeable battery, a power management module 121, a control circuit 122, and an adjustable matching capacitor 123. The control circuit 122 comprises a pulse width modulation (PWM) generator that supplies a square wave signal having an adjustable frequency in the range of 100 kHz to 1 MHz, a full-bridge inverter that converts DC to AC and then drives the transmitting coil, and a metal-oxide-semiconductor field-effect transistor (MOSFET) driver that supplies power to the full-bridge inverter.

[0096] In some embodiments, the transmitting coil 110 has a planar shape with a resonant frequency in the range of 1 MHz to 1 GHz. Referring to Figure 4, a signal generator directly generates an AC voltage having the resonant frequency of the power transmitting coil. The control signal is then amplified by a power amplifier before being applied to the transmitting coil. In some embodiments, an automatic antenna tuner connects the output of the power amplifier to the transmitting coil 110. This automatically adjusts the mounted capacitors and inductors so that the transmitting coil 110 matches the resonant frequency.

[0097] In some embodiments, a separate planar resonant coil is provided. This resonant coil is configured parallel to the transmitting coil 110 to amplify the magnetic field strength. This resonant coil is also configured to operate at the same resonant frequency as the transmitting coil 110. [Examples]

[0098] Referring to Figure 5, the wireless electrical stimulation device 100 comprises a receiving coil 102, a power management module 103-1, a pulse stimulation module 103-2, and one or more pairs of electrodes. As previously mentioned, the receiving coil induces an AC voltage in a time-varying magnetic field, which is unsuitable for powering the following circuits. Therefore, the AC voltage is converted to a DC voltage by a rectifier circuit. In some embodiments, the rectifier circuit consists of diodes that block half of the AC wave, resulting in reduced power efficiency. In some embodiments, the rectifier circuit is a full-bridge rectifier, which is more efficient than a single diode. The converted voltage is smoothed by a capacitor. Furthermore, the voltage is regulated to a stable voltage by a low-dropout (LDO) linear regulator. In some embodiments, a boost converter boosts the voltage to a higher level to drive a constant current source. In some embodiments, the pulse stimulation module includes a microcontroller unit (MCU) for wireless communication and pulse parameter setting. A constant current module converts voltage pulses into constant current pulses with different loads.

[0099] Previous studies have shown that amplitude, frequency, and pulse width all affect the performance of electrical stimulation therapy. Generally, a pulse train consists of a series of pulse signals with constant intervals and constant pulse widths. In some embodiments, the pulses are single-phase signals. However, accumulated charge can lead to muscle fatigue. In some embodiments, the stimulation signal is a two-phase pulse, as shown in Figure 6a, which ensures even charging of the tissue. In some embodiments, the stimulation signal is a voltage pulse, which applies a pulse with a constant voltage amplitude to the tissue. Parasitic capacitance between tissue electrodes causes the charging current to change during stimulation. Overcharging poses associated safety problems. In some embodiments, the stimulation signal is a current pulse, typically in the range of 3mA to 8mA, as shown in Figure 6b. Previous studies have shown that low-frequency electrical stimulation can induce effective muscle movement. Specifically, the frequency is in the range of 1Hz to 1000Hz. In some embodiments, both the frequency and pulse width can be adjusted by an MCU, as shown in Figures 7a, 7b, 7c, and 7d.

[0100] In some embodiments, the wireless electrical stimulation device includes a wirelessly rechargeable battery. The rechargeable battery has a capacity ranging from 1 mAh to 2000 mAh and supplies power to the entire circuit over a typical period ranging from 5 to 60 minutes. [Examples]

[0101] Referring to Figure 8A, in some embodiments, a typical radioelectric stimulator 100 comprises a stent 101 as a mechanical framework, an elastic coil 102 as a receiving coil, and a retractable pulse generator 103 with one or more pairs of electrodes. In Figure 8B, the elastic coil is manufactured by injecting liquid metal into a single silicone tube. The elastic coil is then braided along the framework of the stent. The retractable pulse generator is manufactured from a flexible and pliable material. In some embodiments, dielectric materials such as polydimethylsiloxane (PDMS), polyurethane (PU), styrene-ethylenebutylene styrene (SEBS), and hydrogels are used as substrates and seals. Intrinsic conductive materials are used to form circuit traces and contact pads. In some embodiments, intrinsic conductive materials include, but are not limited to, silver nanowires, carbon nanotubes, gold nanowires, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), or liquid metal. In some embodiments, the electrical stimulator is coated with a parylene layer or an antimicrobial hydrogel layer. Referring to Figure 8C, a typical prototype of a stretchable circuit is subjected to various deformations such as twisting, bending, and stretching. Referring to Figure 8D, the inherent materials and deformable structure work together to enable the integrated wireless electrical stimulation device to withstand a 50% stretch. [Examples]

[0102] Referring to Figure 9, non-invasive endoscopic delivery via a natural orifice is provided. In some embodiments, the radioelectric stimulator 100 is integrated onto a stent. First, the stent with the stimulator is compressed within the delivery catheter 130. The catheter is then delivered through the natural orifice. After the stent is released, the self-expanding stent structure helps to hold the device inside the narrow channel. Finally, the balloon catheter 132 inflates, fully releasing the radioelectric stimulator and allowing the electrode to make contact with the tissue. In some embodiments, the electrode is fabricated in the shape of a microneedle and then inserted through the mucosal layer, with the needle tip in contact with the muscle layer. In some embodiments, the electrode is attached to the outer layer of the stent. The electrode makes direct contact with the tissue as the stent applies a normal force to the tissue.

[0103] In some embodiments, the electrodes are in direct contact with the target muscle group. In some embodiments, the electrodes are manufactured in the shape of microneedles that penetrate the tissue to effectively deliver electrical stimulation. The length of the microneedles ranges from 300 μm to 800 μm. The diameter of the microneedles ranges from 100 μm to 600 μm.

[0104] Referring to Figure 10A, a delivery catheter 130 for non-invasive endoscopic delivery is provided. Generally, the delivery catheter 130 consists of a balloon 132, a flexible catheter 133, a soft tip 131, a block ring 134, a flexible shell 135, and a handle 136. Referring to Figure 10B, the stent is compressed and loaded between the flexible tube 133 and the cover tube 135. During surgery, the surgeon releases the stent by grasping the handle 136 and pulling the cover tube. The block ring 134 prevents the stent from retracting due to friction during the release process. In some embodiments, the procedure is performed under X-ray conditions. A radio marker indicates the position of the stent under X-ray images. In some embodiments, the delivery catheter includes a small camera located at the head of the flexible tip. The illumination of an LED array around the camera provides an endoscopic view for surgery, thereby avoiding exposure to ionizing radiation and increasing the success rate of the delivery procedure in the in vivo environment in darkness. [Examples]

[0105] Referring to Figure 11, an alternative design of the wireless electrical stimulation device 200 is provided. Figure 11A shows a top view of the wireless electrical stimulation device described above. This wireless electrical stimulation device comprises a flexible or pliable substrate 201, a printed receiving coil 202, an electronic component 203, and a printed antenna 204 for wireless communication. In some embodiments, the wireless electrical stimulation device may further comprise a pressure sensing module 205 and / or a rechargeable battery 206. Figure 11B shows a bottom view of the wireless electrical stimulation device described above. This wireless electrical stimulation device further comprises another part of the printed receiving coil 202, one or more electrical stimulation electrodes 207-1, and a reference electrode 207-2. In some embodiments, it may further comprise one or more electrical sensing electrodes 208.

[0106] In some embodiments, the electronic component 203 includes a microcontroller for processing data from the sensor, controlling the stimulation module, and for wireless communication via a radio frequency protocol.

[0107] Referring to Figures 12A and 12B, the associated delivery tool 160 is provided as a whole. The delivery tool comprises a soft tip 162 and a transparent holder 161. The delivery tool is designed to be assembled to a standard endoscope 150 shown in Figure 12C for minimally invasive oral delivery. [Examples]

[0108] Referring to Figure 13, an endoscopic technique for minimally invasive implantation is also disclosed. In some embodiments, the wireless electrical stimulator 200 is implanted in the esophagus for the treatment of gastroesophageal reflux disease (GERD). As shown in Figure 13A, first, a submucosal tunnel is created. The endoscope 150 is inserted through the esophagus 140. An initial incision 141 is created in the esophageal lining. This allows the endoscope to enter the esophageal wall where the muscle is exposed. In Figure 13B, the electrical stimulator 200 is delivered by the delivery tool 160 and implanted in the tunnel 141 between the muscular layer and the mucosal layer. The exposed electrodes are in direct contact with the esophageal muscle to effectively deliver electrical stimulation. At the end of the technique, the esophageal incision is closed with an endoscopic clip 170, as shown in Figure 13C. [Examples]

[0109] Related applications for wireless electrical stimulation systems and delivery methods for endoscopic examinations are also provided. Natural orifices include, but are not limited to, the digestive tract, urinary tract, trachea, and vagina. In some embodiments, the electrical stimulator is implanted in the esophagus for the treatment of GERD. In some embodiments, the electrical stimulator is implanted in the stomach for the treatment of obesity or gastroparesis. In some embodiments, the electrical stimulator is implanted in the small intestine for the treatment of irritable bowel disease. In some embodiments, the electrical stimulator is implanted near the anal sphincter for the treatment of fecal incontinence. In some embodiments, the electrical stimulator is delivered via the urinary tract and implanted in the bladder for the treatment of urinary incontinence. In some embodiments, the electrical stimulator is delivered via the vagina to restore normal function of the pelvic floor muscles.

Claims

1. A system for stimulating target tissue with electrical signals, a. A wireless power transmission module configured to operate at a resonant frequency, comprising one or more wearable transmitting coils and a portable control circuit, b. A deformable radioelectric stimulator configured to be placed on a target and to operate at the resonant frequency, comprising at least one receiving coil, a power management module, and a stimulating module. Equipped with, A system in which the wireless power transmission module generates an alternating magnetic field that passes through the at least one receiving coil, thereby inducing an alternating voltage that is converted into a stable voltage by the power management module, thereby supplying power to the stimulation module and generating the electrical signal.

2. The aforementioned portable control circuit a. A rechargeable battery, a power management circuit supplying constant current and different voltages, a pulse width modulation generator, a full-bridge inverter, a metal-oxide-semiconductor field-effect transistor (MOSFET) driver, and one or more matching capacitors, or b. A rechargeable battery, a power management circuit, a signal generator, a power amplifier, and an automatic antenna tuner comprising one or more wearable transmitting coils operating at the resonant frequency. The system according to claim 1, comprising:

3. The system according to claim 1, wherein the resonant frequency is in the range of 100 kHz to 1 GHz.

4. The aforementioned electrical signal a. Single-phase or two-phase voltage pulses or pulse trains, b. Single-phase or two-phase current pulses or pulse trains, c. Charge-equilibrium current pulse or pulse train The system according to claim 1, comprising:

5. The aforementioned electrical signal a. Current amplitude in the range of 3mA to 15mA, b. Frequencies in the range of 1 Hz to 1000 Hz, and c. Pulse width in the range of 100 microseconds to 200 milliseconds The system according to claim 1, comprising one or more sets of parameters selected from the group consisting of the following.

6. The system according to claim 1, wherein the stimulation module comprises one or more electrodes for delivering the electrical signal to the target tissue.

7. One or more electrodes, a. The one or more electrodes are needle-shaped. b. The one or more electrodes are spaced 0.1 mm to 30 mm apart, and c. The one or more electrodes have a length in the range of 50 μm to 300 μm. The system according to claim 1, comprising one or more features selected from the group consisting of the following.

8. The power management module includes a rectifier circuit for converting the AC voltage into the stable voltage, and the rectifier circuit is a. Multiple diodes and capacitors, b. Full-bridge rectifier, c. Low-dropout linear regulator, d. A boost converter for increasing the stable voltage, and e. A step-down converter that reduces the stable voltage. The system according to claim 1, selected from the group consisting of the following.

9. The deformable wireless electrical stimulation device, Natural ostia selected from the group consisting of the digestive tract, trachea, urinary tract, and vagina. The system according to claim 1, which is adapted to be positioned on the target via the aforementioned.

10. The deformable wireless electrical stimulation device, a. Setting the parameters of the electrical signal, b. Controlling the stimulus module, and c. Processing data for wireless communication via radio frequency protocols. The system according to claim 1, further comprising a microcontroller configured to perform one or more functions selected from the group consisting of the following.

11. The system according to claim 1, further comprising a deformable wireless electrical simulator, a sensing module configured to monitor motion or pressure within the object.

12. The system according to claim 1, wherein the deformable wireless electrical stimulator further comprises one or more sensing electrodes configured to measure electrophysiological signals of the target tissue.

13. The system according to claim 1, wherein the one or more wearable transmitting coils are selected from the group consisting of a single solenoid, a planar coil, a pair of Helmholtz coils, a pair of solenoid coils braided with a single wire, and a planar coil having an additional resonator coil configured to operate at the same resonant frequency.

14. The system according to claim 1, wherein the deformable wireless electrical stimulator further comprises a mechanical frame, and the at least one receiving coil is an elastic coil braided along the mechanical frame.

15. The system according to claim 14, wherein the deformable radio-electrical stimulator is made of a material that allows the deformable radio-electrical stimulator to stretch by up to 50%.

16. Examples of the aforementioned materials include dielectric materials for substrates and encapsulation, as well as specific conductive materials for circuit tracing and contact pads. a. The dielectric material is selected from the group consisting of polydimethylsiloxane (PDMS), polyurethane (PU), styrene-ethylene-butylene-styrene (SEBS), polyimide (PI), polyethylene terephthalate (PET), and hydrogel. b. The system according to claim 15, wherein the intrinsic conductive material is selected from the group consisting of silver nanowires, carbon nanotubes, gold nanowires, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), printed copper wire, and gallium-based liquid metal.

17. A method for delivering the system described in claim 1 to the target organization, a. A step of inserting a delivery tool through an opening to a desired position, wherein the delivery tool comprises a balloon and a stent that is compressed within the delivery tool, and the stent is integrated with the deformable radioelectric stimulation device, b. The step of releasing the stent integrated with the wireless electrical stimulation device, c. The step of inflating the balloon so that the stimulation module comes into contact with the target tissue. A method that includes this.

18. The method according to claim 17, wherein the opening is a natural ophthalmology selected from the group consisting of the digestive tract, trachea, urinary tract, and vagina.

19. The method according to claim 17, wherein the delivery tool further comprises a flexible shell, a soft tip, a block ring, and a balloon equipped with a flexible catheter.

20. A method for delivering the system described in claim 1 to the target organization, a. A step of creating a submucosal tunnel between the mucosal layer and the muscular layer using a standard endoscope, b. The step of assembling the deformable wireless electrical stimulator onto a delivery tool connected to the standard endoscope, c. The step of inserting the deformable wireless electrical stimulator into the submucosal tunnel, d. The step of configuring the deformable wireless electrical stimulator so that an electrical signal is delivered to the target tissue, e. The step of closing the submucosal tunnel. A method that includes this.

21. The method according to claim 20, wherein the delivery tool comprises a soft tip and a transparent holder configured to connect the wireless electrical stimulator to a standard endoscope.

22. The method according to claim 20, wherein the target tissue is the muscular layer of the digestive tract, urinary tract, or reproductive system.

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