Vagus nerve stimulator

Abstract

The invention discloses a vagus nerve stimulator, and relates to the field of medical equipment, and the vagus nerve stimulator comprises a flexible substrate, and an energy collection module, a sensing module and a pulse transmitting module which are all disposed on the flexible substrate. The energy collecting module is connected with the sensing module and the pulse transmitting module. The energy collection module and the sensing module are both wrapped on the left carotid artery; the energy collection module is used for converting mechanical energy generated by relaxation and contraction of the left carotid artery, the temperature difference between the interior of the human body and the skin surface, the temperature difference between the interior of the human body and the environment or chemical energy in the human body into electric energy. The sensing module is used for collecting left carotid artery pressure; the pulse transmitting module is used for generating electric pulses according to the left carotid artery pressure collected by the sensing module and conducting electric pulse stimulation on the left vagus nerve. According to the application, self-power supply is achieved, epilepsy is actively prevented, only the neck needs to be cut open, and the situation that the infection risk of a patient is increased due to double-incision wounds is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a vagus nerve stimulator. BACKGROUND

[0002] Epilepsy is a common chronic neurological disease, with repeated and spontaneous seizures as the core feature. Mild cases may only have short-term daze, limb numbness or hallucinations. Severe cases may have sudden loss of consciousness, convulsions, falls or urinary incontinence. Vagus nerve stimulator has become a mature and effective auxiliary neuroregulation therapy. It sends regular electrical pulses to the left vagus nerve through a device implanted in the chest and neck, indirectly regulates brain activity, and achieves the purpose of reducing seizures. In addition, vagus nerve stimulation may also improve the comorbid depression and migraine symptoms of patients with epilepsy. The vagus nerve stimulator is divided into an implanted part and an external part. The implanted part includes a pulse generator and an implanted electrode lead. The pulse generator is a small titanium device similar to a heart pacemaker, which contains a battery and electronic components, and is usually implanted in a subcutaneous pocket under the left chest (below the clavicle), which can continuously generate electrical pulses. The implanted electrode lead extends from the chest to the neck through a subcutaneous tunnel, one end connected to the pulse generator, and the other end connected to a spiral electrode (usually containing 2-3 contacts), which is wrapped around the left carotid sheath vagus nerve; The external part includes a programmer for doctors and a magnet watch for patients. Doctors use the programmer to set and adjust the parameters of the implanted vagus nerve stimulator, such as stimulation frequency, pulse width, current intensity, stimulation time interval, etc., to achieve the best therapeutic effect, and at the same time, according to the changes in the patient's condition and physical response, the parameters are optimized in a timely manner. When the patient feels the onset of an attack or has frequent cluster attacks, etc., the implanted vagus nerve stimulator can be manually stimulated through the magnet watch to reduce the occurrence of adverse conditions such as seizures. The magnet watch can start or stop stimulation at any time, which is a supplement to standard stimulation.

[0003] However, the existing vagus nerve stimulator relies on the battery in the implanted pulse generator in the chest for power supply, and the size is large. Once the battery energy is depleted, a secondary surgery is needed to replace the battery, increasing the patient's risk of infection and medical costs. In addition, the existing vagus nerve stimulator cannot actively prevent seizures, but only passively responds after the attack. Finally, the existing vagus nerve stimulator needs to be cut open in the neck and chest, which increases the patient's risk of infection due to double incision trauma. SUMMARY

[0004] The purpose of the present application is to provide a vagus nerve stimulator that can achieve self-power supply, actively prevent seizures, and only needs to be cut open in the neck, avoiding double incision trauma and increasing the patient's risk of infection.

[0005] To achieve the above object, the present application provides the following scheme:

[0006] In a first aspect, the present application provides a vagus nerve stimulator, comprising a flexible substrate and an energy collection module, a sensing module and a pulse emission module, which are all arranged on the flexible substrate;

[0007] The energy collection module is connected with the sensing module and the pulse emission module respectively; the energy collection module and the sensing module are both wrapped on the left carotid artery; the energy collection module is used for converting mechanical energy generated by the dilation and contraction of the left carotid artery into electrical energy, converting the temperature difference between the inside of the human body and the surface of the skin into electrical energy, converting the temperature difference between the inside of the human body and the environment into electrical energy, or converting chemical energy in the human body into electrical energy; the sensing module is used for collecting the left carotid artery pressure; and the pulse emission module is used for generating electrical pulses according to the left carotid artery pressure collected by the sensing module and performing electrical pulse stimulation on the left vagus nerve.

[0008] In an embodiment, when the energy collection module is used for converting mechanical energy generated by the dilation and contraction of the left carotid artery into electrical energy, the energy collection module is an electromagnetic induction generator, a piezoelectric nanogenerator, a triboelectric nanogenerator or a combined generator; the combined generator comprises a piezoelectric nanogenerator and a triboelectric nanogenerator.

[0009] In an embodiment, the sensing module is a piezoelectric nanogenerator, a triboelectric nanogenerator or a pressure sensor.

[0010] In an embodiment, the pulse emission module comprises a pulse emitter and a stimulation electrode connected in sequence, and the stimulation electrode is attached to the left vagus nerve.

[0011] The energy collection module is connected with the pulse emitter; the sensing module is connected with the pulse emitter, the pulse emitter generates electrical pulses according to the left carotid artery pressure collected by the sensing module and transmits the electrical pulses to the stimulation electrode, so that the stimulation electrode performs electrical pulse stimulation on the left vagus nerve.

[0012] In an embodiment, the pulse emitter comprises a feedback control unit and a pulse chip connected in sequence; the feedback control unit and the pulse chip are both connected with the energy collection module; the feedback control unit is connected with the sensing module and is used for generating a stimulation decision instruction according to the left carotid artery pressure collected by the sensing module; and the pulse chip is used for generating electrical pulses according to the stimulation decision instruction, calibrating the generated electrical pulses, and then transmitting the calibrated electrical pulses to the stimulation electrode.

[0013] In an embodiment, the vagus nerve stimulator further comprises: a power management module disposed on the flexible substrate; the energy collection module is connected with the pulse emission module and the sensing module through the power management module.

[0014] In an embodiment, the power management module comprises: a rectifier and voltage stabilizer circuit.

[0015] In an embodiment, the power management module further comprises: an energy storage element connected with the rectifier and voltage stabilizer circuit; the rectifier and voltage stabilizer circuit is connected with the energy collection module, and the energy storage element is connected with the pulse emission module and the sensing module.

[0016] In an embodiment, when the energy collection module is used to convert the temperature difference between the inside of the human body and the skin surface into electrical energy or convert the temperature difference between the inside of the human body and the environment into electrical energy, the energy collection module is a thermoelectric generator.

[0017] In an embodiment, when the energy collection module is used to convert the chemical energy in the human body into electrical energy, the energy collection module is a biofuel cell.

[0018] According to the specific embodiments provided in the present application, the present application has the following technical effects:

[0019] The present application provides a vagus nerve stimulator, which realizes in-vivo energy conversion and collection through an energy collection module, and solves the energy supply problem of the existing vagus nerve stimulator. The sensing module realizes real-time monitoring of seizures by monitoring the carotid artery pressure changes caused by heart rate changes, and the pulse emission module gives corresponding electrical signal stimulation to the left vagus nerve according to the carotid artery pressure detected by the sensing module, thereby realizing active prevention and treatment of epilepsy. Finally, all the modules are integrated on a flexible substrate, so that the vagus nerve stimulator only needs to be implanted through a single neck micro-incision, avoiding double-incision trauma and increasing the risk of infection for patients. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 The vagus nerve stimulator structure schematic diagram provided by the present application;

[0022] Figure 2 The vagus nerve stimulator implantation site schematic diagram provided by the present application;

[0023] Figure 3 A partial enlarged view of the implantation site of the vagus nerve stimulator provided in this application;

[0024] Figure 4 Schematic diagram of the vagus nerve stimulator provided for this application;

[0025] Figure 5 Flowchart of the operation of the vagus nerve stimulator provided for this application.

[0026] Figure numerals: 1-energy collection module, 2-sensing module, 3-power management module, 4-pulse transmission module, 31-rectifier and voltage stabilization circuit, 32-energy storage element, 41-neural electrode, 42-feedback control unit, 43-pulse chip. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0029] The present application provides a vagus nerve stimulator, such as Figures 1 to 4 As shown, it includes: a flexible substrate and an energy collection module 1, a sensing module 2 and a pulse transmission module 4 all arranged on the flexible substrate;

[0030] The energy collection module 1 is connected to the sensing module 2 and the pulse transmitting module 4 respectively; the energy collection module 1 and the sensing module 2 are both wrapped around the left carotid artery (the carotid artery next to the left vagus nerve); the energy collection module 1 is used to convert the mechanical energy generated by the dilation and contraction of the left carotid artery into electrical energy, convert the temperature difference between the inside of the human body and the skin surface into electrical energy, convert the temperature difference between the inside of the human body and the environment into electrical energy, or convert the chemical energy in the human body into electrical energy; the sensing module 2 is used to collect the left carotid artery pressure; the pulse transmitting module 4 is used to generate electrical pulses according to the left carotid artery pressure collected by the sensing module 2 and perform electrical pulse stimulation on the left vagus nerve.

[0031] In actual applications, metal is printed on a flexible substrate, and each module is connected by the printed metal, replacing wires to become a wire-free vagus nerve stimulator.

[0032] In another exemplary embodiment of the present application, when the energy harvesting module 1 is used to convert the mechanical energy generated by the left carotid artery diastole and systole into electrical energy, the energy harvesting module 1 is an electromagnetic induction generator, a piezoelectric nanogenerator, a triboelectric nanogenerator, or a combination generator; the combination generator includes a piezoelectric nanogenerator and a triboelectric nanogenerator.

[0033] The core principle of the piezoelectric nanogenerator is to efficiently convert the applied mechanical strain or stress into electrical energy by using the piezoelectric effect. The typical structure is composed of a piezoelectric material in the middle layer sandwiched between the upper and lower electrode layers. When an external force acts on the piezoelectric material, mechanical deformation occurs inside the material, causing the positive and negative charge centers to shift, resulting in electric polarization. In turn, equal and opposite charges are induced on the surfaces of the material. These surface charges form a piezoelectric potential difference. When the upper and lower electrodes are connected to an external circuit, the potential difference drives the flow of electrons through the external circuit, thereby outputting electrical energy.

[0034] The triboelectric nanogenerator is an electromechanical energy conversion device based on the synergistic effect of triboelectricity and electrostatic induction. The core principle is that when two materials with different electronic affinities come into contact, due to the asymmetric double potential well formed by the overlap of the interface electron cloud, electrons will transfer from the material with low electronegativity to the material with high electronegativity. After separation, the transferred electrons are trapped due to the energy barrier, causing the two material surfaces to carry opposite charges. The accumulation of electric charges produces a potential difference (i.e., triboelectric potential), driving the free electrons in the back electrode of the material to flow through the external circuit to balance the potential, thereby outputting an electric current.

[0035] When the energy harvesting module 1 is a piezoelectric nanogenerator, a triboelectric nanogenerator, or a combination generator, the energy harvesting module 1 uses the surface curvature change generated by the diastole and systole of the carotid artery to cause the nanogenerator to bend accordingly as the carotid artery changes, thereby generating polarized charges to drive free electrons to flow in the peripheral circuit to achieve self-energy supply.

[0036] In practical applications, when the energy harvesting module 1 is used to convert chemical energy in the human body into electrical energy, the energy harvesting module 1 is a biofuel cell.

[0037] In another example embodiment of the present application, the sensing module 2 is composed of a flexible force-electricity conversion device, which is a piezoelectric nanogenerator, a triboelectric nanogenerator or a pressure sensor (constructed by piezoresistive functional materials). The sensing module 2 preferably uses piezoelectric materials or triboelectric materials, and both are flexible materials. The softness and bendability of the sensing module 2 made of flexible materials make it better adapt to the shape of the blood vessel, which can reduce the discomfort of the patient after implantation and improve the acceptance and comfort of the patient. The sensing module 2 is responsible for converting the carotid artery pressure signal into an electrical signal. The specific heart rate caused by epilepsy can be monitored by the sensing module 2 through the change of the carotid artery pressure, so as to monitor the occurrence of epilepsy in real time.

[0038] In another example embodiment of the present application, the pulse emitter module 4 includes a pulse emitter and a stimulation electrode connected in sequence, and the stimulation electrode is attached to the left vagus nerve.

[0039] The energy collection module 1 is connected with the pulse emitter, and the sensing module 2 is connected with the pulse emitter. The pulse emitter generates an electrical pulse according to the left carotid artery pressure collected by the sensing module 2 and transmits it to the stimulation electrode, so that the stimulation electrode stimulates the left vagus nerve with an electrical pulse.

[0040] In another example embodiment of the present application, the pulse emitter includes a feedback control unit 42 and a pulse chip 43 connected in sequence. The feedback control unit 42 and the pulse chip 43 are both connected with the energy collection module 1. The feedback control unit 42 is connected with the sensing module 2 and is used to generate a stimulation decision instruction according to the left carotid artery pressure collected by the sensing module 2. The pulse chip 43 is used to generate an electrical pulse according to the stimulation decision instruction, calibrate the generated electrical pulse, and then transmit it to the stimulation electrode. The feedback control unit 42 continuously monitors the change of the carotid artery pressure, identifies the specific abnormality of the heart rate during epilepsy through an embedded analysis algorithm, and generates a stimulation decision instruction in real time. The pulse chip 43 generates an accurate electrical pulse based on the instruction, which is transmitted to the left vagus nerve through the stimulation electrode after dynamic calibration. The stimulation electrode is attached to the left vagus nerve, and the stimulation electrode is made of biocompatible materials to ensure the safety and effectiveness of the stimulation process.

[0041] In another example embodiment of the present application, the vagus nerve stimulator further includes a power management module 3 arranged on the flexible substrate. The energy collection module 1 is connected with the pulse emitter module 4 and the sensing module 2 through the power management module 3.

[0042] In another example embodiment of the present application, the power management module 3 includes a rectifier and voltage stabilizing circuit 31.

[0043] In another example embodiment of the present application, the power management module 3 further comprises an energy storage element 32 connected to the rectifier and voltage stabilizing circuit 31; the rectifier and voltage stabilizing circuit 31 is connected to the energy harvesting module 1, and the energy storage element 32 is connected to the pulse emission module 4 and the sensing module 2. The rectifier and voltage stabilizing circuit 31 rectifies, converts voltage and manages energy storage of the electrical energy obtained by the energy harvesting module 1, converts irregular micro-amplitude alternating current signals into stable direct current voltage and charges the energy storage element 32, while implementing overvoltage or undervoltage protection to maintain energy storage safety; the energy storage element 32 is used to provide energy for the entire system and pulse emission.

[0044] In actual application, the energy storage element 32 is connected to the feedback control unit 42, which is used to monitor the energy storage state in real time.

[0045] In another example embodiment of the present application, the piezoelectric nanogenerator, the triboelectric nanogenerator and the pressure sensor are all flexible materials.

[0046] In another example embodiment of the present application, the electromagnetic induction generator comprises a magnet and a coil, the magnet is sleeved in the coil, and the magnet is arranged in contact with the left carotid artery and moves relative to the coil with the pulsation of the left carotid artery. A micro magnet and a coil are placed beside the carotid artery, and the pulsation of the carotid artery causes the relative movement of the magnet and the coil, resulting in the change of the magnetic flux passing through the coil and the generation of current. The output current of the electromagnetic induction generator is more stable and has higher power density.

[0047] In actual application, when the energy harvesting module 1 is used to convert the temperature difference between the inside of the human body and the skin surface into electrical energy or convert the temperature difference between the inside of the human body and the environment into electrical energy, the energy harvesting module 1 is a thermoelectric generator.

[0048] In actual application, the thermoelectric generator generates electricity by using the small temperature difference between the inside of the human body (such as the deep tissue of the neck) and the skin surface or the environment. The thermoelectric generator is implanted beside the vagus nerve, but may need to be closer to the skin. This power generation method has a relatively simple structure and no moving parts, and can provide continuous power.

[0049] The vagus nerve stimulator provided by the present application has the following operation process after being implanted through a single incision in the neck: Figure 5As shown, the energy collection module 1 is directly wrapped on the outer wall of the carotid artery, and the periodic curvature change generated by the carotid artery pulse is used to drive the nanogenerator to bend and deform, so that mechanical energy is converted into alternating current signals; the electrical energy is stored in the energy storage element 32 after being processed by the rectification and voltage stabilization circuit 31, so that the device can run self-powered without external energy supply. The sensing module 2 is synchronously wrapped on the outer wall of the carotid artery, and the carotid artery pressure fluctuation is converted into a heart rate signal in real time by capturing the micro-strain of the blood vessel wall. The feedback control unit 42 continuously analyzes the epilepsy-specific features in the signals collected by the sensing module 2, and triggers a control instruction as soon as epilepsy is identified. The pulse chip 43 generates an electric pulse with adjustable parameters based on the instruction, and applies it to the vagus nerve through a biocompatible stimulating electrode, so that the intervention is completed within the seizure latency. All functional modules are integrated on a single flexible substrate, and the ultra-thin and flexible characteristics ensure conformal attachment to the carotid-nerve anatomical structure, forming a closed-loop autonomous system.

[0050] The energy collection module 1 in the vagus nerve stimulator provided in the present application converts the mechanical energy of the carotid artery pulse into electrical energy or converts the chemical energy in the human body into electrical energy, has self-powering capability, breaks away from the dependence on traditional batteries, avoids the risk of secondary surgery caused by battery depletion, significantly reduces the incidence of long-term complications such as patient infection and tissue damage, and improves lifelong treatment compliance.

[0051] The sensing module 2 converts the carotid artery pressure change into an electrical signal in real time, realizing rapid physiological signal capture. Combined with an embedded recognition algorithm, epilepsy-specific heart rate abnormalities can be captured in real time, and precise electric pulse stimulation can be triggered within the seizure latency. Real-time pattern recognition of epilepsy-specific heart rate changes triggers electric pulse stimulation to start intervention within the seizure latency, forming a "perception-decision-treatment" closed-loop autonomous system, breaking through the blind area of traditional periodic stimulation, effectively inhibiting the intensity and duration of seizures, and achieving effective inhibition of seizures as well as real-time diagnosis and treatment.

[0052] The energy collection module 1, the sensing module 2, the pulse emission module 4, and the power management module 3 are integrated on a biocompatible flexible substrate, realizing miniaturization of the device, so that the vagus nerve stimulator only needs to be implanted through a single neck micro-incision, realizing conformal attachment to the carotid-vagus nerve. Minimally invasive implantation increases the convenience of surgical operation, greatly reduces the risk of infection and the risk of vascular or nerve side damage, and the flexible design avoids mechanical compression of the pulsating blood vessels and reduces tissue rejection.

[0053] The technical features of the above embodiments can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0054] The principles and implementation manners of the present application are described herein by using specific examples, and the above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will have changes. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A vagus nerve stimulator, characterized in that: The vagus nerve stimulator includes: a flexible substrate and an energy collection module, a sensor module and a pulse transmission module all arranged on the flexible substrate; The energy collection module is respectively connected to the sensing module and the pulse transmitting module; the energy collection module and the sensing module are both wrapped around the left carotid artery; the energy collection module is used to convert the mechanical energy generated by the dilation and contraction of the left carotid artery into electrical energy, convert the temperature difference between the inside of the human body and the skin surface into electrical energy, convert the temperature difference between the inside of the human body and the environment into electrical energy, or convert the chemical energy in the human body into electrical energy; the sensing module is used to collect the left carotid artery pressure; the pulse transmitting module is used to generate electrical pulses according to the left carotid artery pressure collected by the sensing module and perform electrical pulse stimulation on the left vagus nerve.

2. The vagus nerve stimulator according to claim 1, characterized in that When the energy collection module is used to convert the mechanical energy generated by the dilation and contraction of the left carotid artery into electrical energy, the energy collection module is an electromagnetic induction generator, a piezoelectric nanogenerator, a triboelectric nanogenerator or a combined generator; the combined generator includes a piezoelectric nanogenerator and a triboelectric nanogenerator.

3. The vagus nerve stimulator according to claim 1, wherein The sensing module is a piezoelectric nanogenerator, a triboelectric nanogenerator or a pressure sensor.

4. The vagus nerve stimulator according to claim 1, wherein The pulse transmitting module includes a pulse transmitter and a stimulation electrode connected in sequence, and the stimulation electrode is attached to the left vagus nerve; The energy collection module is connected to the pulse transmitter; the sensor module is connected to the pulse transmitter, and the pulse transmitter generates an electrical pulse based on the left carotid artery pressure collected by the sensor module and transmits it to the stimulation electrode, so that the stimulation electrode performs electrical pulse stimulation on the left vagus nerve.

5. The vagus nerve stimulator according to claim 4, characterized in that The pulse transmitter includes: a feedback control unit and a pulse chip connected in sequence; the feedback control unit and the pulse chip are both connected to the energy collection module; the feedback control unit is connected to the sensing module, and is used to generate a stimulation decision instruction based on the left carotid artery pressure collected by the sensing module; the pulse chip is used to generate an electrical pulse according to the stimulation decision instruction, and after calibrating the generated electrical pulse, transmit it to the stimulation electrode.

6. The vagus nerve stimulator according to claim 1, characterized in that The vagus nerve stimulator further includes: a power management module arranged on the flexible substrate; the energy collection module is connected to the pulse emission module and the sensor module through the power management module.

7. The vagus nerve stimulator according to claim 6, characterized in that The power management module includes a rectifier and voltage stabilization circuit.

8. The vagus nerve stimulator according to claim 7, characterized in that The power management module further includes: an energy storage element connected to the rectifier and voltage stabilization circuit; the rectifier and voltage stabilization circuit is connected to the energy collection module, and the energy storage element is connected to the pulse emission module and the sensor module.

9. The vagus nerve stimulator according to claim 1, characterized in that When the energy collection module is used to convert the temperature difference between the inside of the human body and the skin surface into electrical energy or to convert the temperature difference between the inside of the human body and the environment into electrical energy, the energy collection module is a thermoelectric generator.

10. The vagus nerve stimulator according to claim 1, characterized in that When the energy collection module is used to convert chemical energy in the human body into electrical energy, the energy collection module is a biofuel cell.

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