Noninvasive bilateral hypoglossal nerve constant-current electrical stimulator

Abstract

The invention belongs to the technical field of medical instruments, and discloses a noninvasive bilateral hypoglossal nerve constant-current electrical stimulator which comprises an electrode plate A, a wire, a stimulation controller and an electrode plate B, the right of the upper end of the stimulation controller is connected with the electrode plate A; the center of the upper end of the stimulation controller is connected with the electrode plate B through a wire. The blood oxygen saturation degree signal of a patient can be sensed, an electric signal can be sent, hypoglossal nerves are stimulated through the electrode plate attached to the surface of the lower jaw, upper airway muscles of the patient are made to contract, the purpose of treating obstructive sleep apnea is achieved, and the snoring condition can be improved. According to the invention, hypoglossal nerves are noninvasively stimulated; the instrument can be worn and taken off at any time according to subjective willingness of a patient. The intensity of electrical stimulation is automatically adjusted according to whether the oxyhemoglobin saturation signal exists or not. The hypoglossal nerve is stimulated in a non-invasive mode, the comfort level is high, and the general anesthesia operation and infection risks needed by subcutaneous implantation of a constant-current electrical stimulator are avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a non-invasive bilateral hypoglossal nerve constant current electrical stimulator. Background Art

[0002] Obstructive sleep apnea (OSA) is a condition characterized by repetitive nocturnal upper airway collapse. Currently, a subcutaneously implanted hypoglossal nerve constant-current electrical stimulator has been approved by the US Food and Drug Administration for the treatment of OSA patients. However, subcutaneous implantation is an invasive procedure requiring approximately 90-120 minutes of general anesthesia. Patients who wish to discontinue use of the device must undergo another surgery, and the implanted device carries the risk of infection and displacement.

[0003] Currently, the closest existing technologies are mainly unilateral hypoglossal nerve electrical stimulation devices or implantable hypoglossal nerve stimulation systems. For example, the implantable stimulator disclosed in the literature surgically fixes electrodes near the hypoglossal nerve and cooperates with an in-vivo pulse generator to achieve constant current output to treat functional disorders such as obstructive sleep apnea (OSA). Although such systems have certain therapeutic effects in terms of neural activation, they are subject to significant problems such as infection risks, high costs, and limited scope of application brought about by invasive operations. At the same time, it is difficult to dynamically adjust stimulation parameters according to individual physiological changes, resulting in insufficient stimulation accuracy and individual adaptability.

[0004] In addition, existing surface electrode devices mostly use a constant voltage drive method, which cannot maintain a constant stimulation current when tissue impedance changes, resulting in fluctuations in stimulation intensity, affecting the stability and controllability of neural responses. At the same time, traditional devices are mostly single-channel designs, lacking the ability to independently regulate the bilateral hypoglossal nerves, making it difficult to adapt to the clinical needs of symmetry and lateralization intervention in neurological function recovery, and unable to achieve selective activation of different functional fibers, restricting its application expansion in various neuromodulation indications. A non-invasive device with constant current output, dual-channel differentiated stimulation and high adhesion is needed to solve the above technical bottlenecks. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a non-invasive bilateral hypoglossal nerve constant current electrical stimulator.

[0006] The present invention is achieved by providing a non-invasive bilateral hypoglossal nerve constant current electrical stimulator, comprising:

[0007] Electrode A, wire, stimulation controller, electrode B;

[0008] The stimulation controller is connected to the electrode sheet A and the electrode sheet B through the wires respectively.

[0009] The stimulation controller is internally provided with a constant current source module for outputting a pulse current of constant amplitude, and is configured with a dual-channel independent output unit to drive the electrode sheet A and the electrode sheet B respectively, supporting synchronous or alternating stimulation modes;

[0010] The stimulation controller also has a pulse parameter modulation function, which can adjust the frequency, amplitude, width, duty cycle and waveform type of the pulse to achieve the typed activation of motor fibers and sensory fibers;

[0011] The electrode sheets A and B are multi-layer flexible adhesive structures, including a conductive layer and a low-resistance gel layer, and are respectively attached to the skin surfaces on the left and right sides of the user's mandibular area, matching the symmetrical course of the hypoglossal nerve to achieve highly conformable non-invasive stimulation;

[0012] The stimulation controller is also provided with an electrode detachment detection module and a contact impedance monitoring module, which are used to evaluate the attachment status in real time and issue an alarm prompt in abnormal situations.

[0013] Furthermore, the constant current source module includes a feedback adjustment unit and a voltage control unit, which are used to adjust the output voltage in real time based on the electrode load impedance to ensure the stability of the output pulse current.

[0014] Furthermore, the stimulation controller has a dual-channel independent output module, supports synchronous stimulation mode and alternating stimulation mode, and allows the output parameters of the two channels to be set separately.

[0015] Furthermore, the electrode sheet A and the electrode sheet B both include a flexible conductive layer and a conductive gel layer, and are symmetrically arranged in the mandibular area according to the anatomical direction of the hypoglossal nerve.

[0016] Furthermore, the stimulation controller has a built-in safety monitoring module for detecting wire short circuit, electrode detachment and output overcurrent, and automatically stops output and issues an alarm when an abnormality is detected.

[0017] The present invention also provides a control method for a non-invasive bilateral hypoglossal nerve constant current electrical stimulator, comprising the following steps:

[0018] Step 1: Collect the wearer's blood oxygen saturation signal through electrode B and transmit it to the stimulation controller;

[0019] Step 2: The stimulation controller analyzes the blood oxygen saturation signal and controls the electrode A to emit a constant current electrical stimulation signal to stimulate the hypoglossal nerve;

[0020] Step 3: When the blood oxygen saturation signal still persists, the stimulation controller increases the stimulation intensity of electrode A;

[0021] Step 4: When the decrease in blood oxygen saturation exceeds a set time limit, the stimulation controller reduces the stimulation intensity by one level.

[0022] Furthermore, the stimulation controller is provided with a blood oxygen saturation monitoring module for identifying a blood oxygen saturation characteristic signal and comparing it with a set threshold to determine whether to trigger a stimulation response.

[0023] Furthermore, within the effective time period of electrical stimulation, when the blood oxygen saturation signal does not decrease for 2 minutes, the stimulation controller controls the stimulation current amplitude to increase step by step, and the increase amplitude is a set value.

[0024] Furthermore, when the blood oxygen saturation signal does not disappear and does not significantly increase for 2 consecutive minutes, the stimulation controller controls the electrode sheet A to output electrical stimulation that is reduced by one level.

[0025] Furthermore, the stimulation controller dynamically corrects the output current in combination with the real-time detection results of the electrode contact impedance while receiving the blood oxygen saturation feedback signal to ensure the accuracy and safety of the stimulation.

[0026] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0027] First, the present invention can sense the patient's blood oxygen saturation and send electrical signals to stimulate the hypoglossal nerve through electrodes attached to the surface of the mandible, causing the patient's upper airway muscles to contract, thereby achieving the purpose of treating obstructive sleep apnea and improving snoring.

[0028] The present invention non-invasively stimulates the hypoglossal nerve;

[0029] The present invention allows patients to wear and remove the device at any time according to their subjective wishes.

[0030] The present invention automatically adjusts the intensity of electrical stimulation according to the presence or absence of blood oxygen saturation.

[0031] The present invention stimulates the hypoglossal nerve in a non-invasive manner, is highly comfortable, and avoids the general anesthesia surgery and infection risks required for subcutaneous implantation of a constant current electrical stimulator.

[0032] Second, the first-line treatment for sleep apnea is a home ventilator, but approximately half of patients abandon treatment within the first year due to inability to adhere to it. Upper airway surgery is a second-line option, which is invasive, has limited effectiveness, and is prone to relapse. Implantable hypoglossal nerve stimulation can improve sleep apnea, but requires general anesthesia. This invention offers a non-invasive and well-tolerated treatment option for sleep apnea patients, potentially bringing both public health benefits and commercial value.

[0033] The present invention stimulates the hypoglossal nerve in a non-invasive manner, thereby maintaining the patency of the patient's upper airway.

[0034] The present invention stimulates the hypoglossal nerve by delivering constant current electrical stimulation, which causes less stimulation to the patient, less interference with sleep, and has a strong ability to resist impedance changes.

[0035] The present invention provides a non-invasive treatment method with better expected therapeutic effects for patients with sleep apnea. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a structural diagram of a non-invasive bilateral hypoglossal nerve constant current electrical stimulator provided by an embodiment of the present invention.

[0037] Figure 2 This is a flow chart of a control method for a non-invasive bilateral hypoglossal nerve constant current electrical stimulator provided by an embodiment of the present invention.

[0038] Figure 1 Middle: 1. Electrode A; 2. Lead wire; 3. Stimulation controller; 4. Electrode B. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] Example 1

[0041] This embodiment uses disposable medical hydrogel electrodes as electrode sheets A and B. Each sheet has an adhesive area of ​​approximately 20mm x 25mm and a thickness of 1mm. It can be applied to the skin surface below the hyoid bone, symmetrically on both sides. The wires are Φ1.2mm silicone insulated double-stranded soft wires, and the pins and stimulation controller 3 use LEMO self-locking interfaces to ensure quick plugging and unplugging and 360° rotation without entanglement. The constant current source module is based on a 16-bit DAC and an isolated buck-boost power supply. The output current is continuously adjustable from 0 to 10mA, with a minimum step of 0.05mA and a dynamic load range of 100Ω to 2.5kΩ. It also has a built-in 24V transient suppression tube and overcurrent fuse for dual current limiting protection.

[0042] In preclinical testing, electrodes were applied to the bilateral hypoglossal muscles of eight volunteers, with settings set at a pulse width of 200μs, a frequency of 30Hz, a peak of 2mA, and a duty cycle of 50%. Real-time monitoring revealed that current variation was <±2% when the load impedance fluctuated by ±35%. Electromyography revealed symmetrical contraction of the hypoglossal muscles bilaterally, and subjective scores indicated no significant pain. Continuous stimulation for 30 minutes resulted in no erythema or burning on the skin, verifying the constant current accuracy and epidermal compatibility.

[0043] Example 2

[0044] This embodiment is designed for people with sleep-disordered breathing. Electrode pads A / B utilize a 15mm x 20mm, integrated, washable, reusable medical fiber cloth and gel electrode. An NTC sensor is embedded in the back for closed-loop skin temperature monitoring. Wire 2 utilizes a 0.8mm ultra-flexible FEP flat wire with a detachable NI-MH magnetic connector, facilitating easy turning while sleeping. Stimulation controller 3 integrates a Bluetooth BLE module and a 3-axis accelerometer, synchronizing breathing and body position information with a mobile phone app. The constant current source utilizes an adaptive switching constant current structure, outputting 0.5 to 6 mA with an error of <±1%. It also supports 2kHz high-frequency carrier modulation to reduce skin impedance.

[0045] In a wearable overnight trial in 12 patients with mild to moderate obstructive sleep apnea, the stimulation window was set to a 100ms delay with the respiratory phase, with a current of 1.5mA, a pulse width of 150μs, and a frequency of 20Hz. Recordings throughout the night (average 6.7 hours) showed 100% device compliance, a decrease in the average AHI from 21.3 to 8.4, and a 63% reduction in tongue base collapse events. The closed-loop temperature function controlled skin temperature rise to <1.2°C. A subsequent inspection revealed no indentation or edema, and the average user satisfaction questionnaire score (on a 1–5 scale) was 4.6, demonstrating the feasibility of this embodiment in terms of long-term comfort and efficacy.

[0046] like Figure 1 As shown, the embodiment of the present invention provides a non-invasive bilateral hypoglossal nerve constant current electrical stimulator comprising:

[0047] Electrode A1, wire 2, stimulation controller 3, electrode B4;

[0048] The right side of the upper end of the stimulation controller 3 is connected to the electrode A1 through the wire 2;

[0049] The center of the upper end of the stimulation controller 3 is connected to the electrode B4 through the wire 2.

[0050] The stimulation controller integrates a constant current source module with dynamic resistance matching and voltage regulation, maintaining a constant stimulation current output under varying tissue resistance conditions. This constant current output mechanism ensures precise control of current amplitude, preventing variations in stimulation intensity due to tissue impedance fluctuations, and improving the controllability and safety of neural stimulation.

[0051] The controller features two independent output channels, driving electrodes A and B respectively. These channels can deliver simultaneous or alternating outputs, with output parameters including pulse current amplitude, frequency, and width preset to suit clinical needs. This design enables precise and differentiated stimulation of the bilateral hypoglossal nerves, facilitating balanced neuromodulation and personalized intervention outcomes.

[0052] Electrode Pads A and B are surface-attached, multi-layer structures featuring a flexible conductive layer and a low-resistance interfacial gel layer. They adhere closely to the skin's surface, enabling non-invasive and precise targeting of nerve pathways in the sublingual region. The electrodes are symmetrically attached to the mandibular area, following the course of the hypoglossal nerve. The contact area design optimizes current density distribution, enhancing targeted stimulation and comfort.

[0053] The stimulation controller can output single-phase or biphasic rectangular pulses with both frequency modulation (FM) and amplitude modulation (AM) capabilities. By adjusting pulse waveform parameters (such as starting current, ramp time, and duty cycle), differential activation of the motor and sensory fibers of the hypoglossal nerve can be achieved. This pulse modulation mechanism enhances stimulation selectivity and the ability to regulate neuroplasticity.

[0054] The controller features built-in overcurrent protection, short-circuit detection, and electrode detachment monitoring units, providing real-time assessment of output circuit status. If an anomaly is detected, the system immediately interrupts output and issues an audible and visual alert to ensure user safety. Furthermore, the controller supports electrode contact impedance measurement, providing dynamic feedback on attachment status and providing a basis for parameter optimization.

[0055] This device is primarily used to stimulate the hypoglossal nerve, triggering nerve depolarization and inducing muscle contraction through low-frequency, constant-current electrical stimulation. It has broad application in sleep apnea intervention, dysphagia rehabilitation, and tongue motor dysfunction treatment, demonstrating its technological advancement and practicality in the field of non-invasive neuromodulation.

[0056] like Figure 2 As shown, the present invention provides a non-invasive bilateral hypoglossal nerve constant current electrical stimulation device control method comprising:

[0057] S101, the patient's blood oxygen saturation signal is sensed through electrode B, and the signal is transmitted to the stimulation controller through the wire;

[0058] S102: The program in the stimulation controller controls electrode A to send a constant current electrical stimulation to stimulate the hypoglossal nerve and open the upper airway. If the blood oxygen saturation signal is still present, the signal is transmitted to the stimulation controller again, and the electrical stimulation delivered by electrode A is enhanced.

[0059] S103, if the blood oxygen saturation signal does not decrease for 2 minutes, the stimulation controller controls the constant current electrical stimulation delivered by electrode A to be reduced by one level.

[0060] In response to the problems of existing hypoglossal nerve electrical stimulation devices, such as unstable output current, inaccurate stimulation area positioning, single stimulation mode and insufficient safety, the present invention proposes a non-invasive bilateral hypoglossal nerve constant current electrical stimulator with constant current control, dual-channel independent adjustment and non-invasive precise attachment characteristics, aiming to improve the stability of nerve regulation, individual adaptability and treatment safety.

[0061] First, to achieve stable and reliable neural depolarization activation, this device integrates a constant current source module within the stimulation controller, creating a dynamic resistance matching and high-voltage tolerance adjustment system. This allows the system to automatically adjust the output voltage based on the instantaneous impedance between the electrode and the skin, thereby continuously outputting the set constant current in a changing load environment. This mechanism avoids the problem of current drift caused by tissue impedance fluctuations and is a key technological breakthrough that traditional voltage-driven stimulation methods struggle to address.

[0062] Secondly, in order to meet the different requirements of the bilateral hypoglossal nerves in anatomical structure and functional response, two sets of independent current control units are installed inside the stimulation controller, corresponding to electrode A and electrode B respectively, which can output pulse signals with independent or coordinated parameters.

[0063] Thirdly, considering the complex structure and large surface curvature of the sublingual skin, the electrode sheet adopts a flexible multi-layer composite structure with a biocompatible conductive film and a low-resistance interface gel layer, ensuring a close fit to the target area in a non-invasive state, forming a stable, low-impedance electrical contact. The electrode sheet shape is designed based on the course of the hypoglossal nerve, and the current density gradient is controlled by the contact area, significantly improving the regional targeting and sensory comfort of stimulation, while reducing the risk of non-target tissue interference and current leakage.

[0064] Furthermore, to enhance the physiological adjustability of the stimulation signal and the depth of functional neural regulation, the system supports single-phase and biphasic rectangular pulse outputs, and features FM (frequency modulation) and AM (amplitude modulation) capabilities. Users can configure parameters such as pulse starting current, rise time, duration, and duty cycle through the interface to match the excitation thresholds of different nerve fiber types, achieving differentiated activation of motor and sensory fibers, thereby inducing more complex muscle group coordinated responses and regulating central nervous system plasticity.

[0065] Furthermore, the system's safety design is particularly prominent. The controller features built-in electrode detachment monitoring, short-circuit detection, and overcurrent protection mechanisms, providing real-time feedback on the output circuit integrity status. Upon detecting a connection anomaly, output anomaly, or sudden change in electrode impedance, the system automatically shuts off the current and issues an audible and visual alarm, effectively preventing potential risks such as thermal injury, electric shock, or nerve overactivation. A high-frequency resistance measurement algorithm assists with fit confirmation, providing the operator with a basis for precise parameter adjustments and improving treatment consistency and repeatability.

[0066] The present invention solves the technical bottlenecks of traditional nerve electrical stimulation equipment in terms of stability, accuracy and controllability through the four-dimensional system integration innovation of electrical stimulation mechanism, electrode structure, output mode and safety protection, and provides an efficient, controllable and safe engineering solution for non-invasive hypoglossal nerve function regulation.

[0067] In completed functional tests of subjects, low-frequency pulse intervention using the non-invasive bilateral hypoglossal nerve constant-current electrical stimulator described in this invention significantly improved tongue mobility index (Tongue Mobility Index) after five consecutive days of stimulation, with an average increase of 22.4%. Among them, the most significant improvements were in tongue tip elevation and lateral flexibility, indicating that the device can effectively induce electromyographic responses in the hypoglossal nerve-driven muscles and enhance their motor coordination ability in the short term.

[0068] In the continuous monitoring experiment of surface electrode contact impedance, the impedance value of the multilayer flexible electrode used quickly stabilized in the range of 1.8 to 2.4 kΩ within 5 minutes after application, which is much lower than the traditional dry electrode system (3.5 to 5.0 kΩ). It still maintains uniform fit and low interface impedance output under dynamic surface tension changes, indicating that it has excellent non-invasive contact performance, providing a physical basis for the stability of constant current stimulation.

[0069] Multiple simulated load experiments addressing output current consistency demonstrated that within a load impedance range of 50Ω to 1500Ω, the output error remained within ±3%, compared to ±18% for conventional constant-voltage devices under the same conditions. This result fully demonstrates the excellent load adaptability of the dynamic voltage-matching constant-current source module integrated in this device, enabling it to maintain high-fidelity stimulation output under varying tissue conductance conditions.

[0070] In a preliminary preclinical study of dysphagia rehabilitation, the stimulator was used to implement a 10-day personalized stimulation program in patients with impaired swallowing function after stroke. The patients' pharyngeal reflex evoked latency decreased from an average of 3.1 seconds to 2.2 seconds, significantly improving their eating efficiency, with no adverse electrical stimulation reactions. This data demonstrates the device's effectiveness in activating relevant sensory and motor pathways and its good biological tolerability, providing support for subsequent large-scale clinical trials.

[0071] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A non-invasive bilateral hypoglossal nerve constant current electrical stimulator, characterized in that: include: Electrode A, wire, stimulation controller, electrode B; The stimulation controller is connected to the electrode sheet A and the electrode sheet B through the wires respectively. The stimulation controller is internally provided with a constant current source module for outputting a pulse current of constant amplitude, and is configured with a dual-channel independent output unit to drive the electrode sheet A and the electrode sheet B respectively, supporting synchronous or alternating stimulation modes; The stimulation controller also has a pulse parameter modulation function, which can adjust the frequency, amplitude, width, duty cycle and waveform type of the pulse to achieve the typed activation of motor fibers and sensory fibers; The electrode sheets A and B are multi-layer flexible adhesive structures, including a conductive layer and a low-resistance gel layer, and are respectively attached to the skin surfaces on the left and right sides of the user's mandibular area, matching the symmetrical course of the hypoglossal nerve to achieve highly conformable non-invasive stimulation; The stimulation controller is also provided with an electrode detachment detection module and a contact impedance monitoring module, which are used to evaluate the attachment status in real time and issue an alarm prompt in abnormal situations.

2. The constant current electrical stimulation device according to claim 1, characterized in that: The constant current source module includes a feedback adjustment unit and a voltage control unit, which are used to adjust the output voltage in real time based on the electrode load impedance to ensure the stability of the output pulse current.

3. The constant current electrical stimulation device according to claim 1, characterized in that: The stimulation controller has a dual-channel independent output module, supports a synchronous stimulation mode and an alternating stimulation mode, and allows the output parameters of the two channels to be set separately.

4. The constant current electrical stimulation device according to claim 1, characterized in that: The electrode sheet A and the electrode sheet B both include a flexible conductive layer and a conductive gel layer, and are symmetrically arranged in the mandibular area according to the anatomical direction of the hypoglossal nerve.

5. The constant current electrical stimulation device according to claim 1, characterized in that: The stimulation controller has a built-in safety monitoring module for detecting wire short circuit, electrode sheet detachment and output overcurrent, and automatically stops output and issues an alarm when an abnormality is detected.

6. A control method for a non-invasive bilateral hypoglossal nerve constant current electrical stimulator, characterized in that: The following steps are involved: Step 1: Collect the wearer's blood oxygen saturation signal through electrode B and transmit it to the stimulation controller; Step 2: The stimulation controller analyzes the blood oxygen saturation signal and controls the electrode A to emit a constant current electrical stimulation signal to stimulate the hypoglossal nerve; Step 3: When the blood oxygen saturation signal still persists, the stimulation controller increases the stimulation intensity of electrode A; Step 4: When the blood oxygen saturation drops below a set threshold, the stimulation controller reduces the stimulation intensity by one level.

7. The control method according to claim 6, characterized in that: The stimulation controller is provided with a blood oxygen saturation detection module for identifying a blood oxygen saturation characteristic signal and comparing it with a set threshold to determine whether to trigger a stimulation response.

8. The control method according to claim 6, characterized in that: During the effective electrical stimulation period, when the blood oxygen saturation signal decreases and persists, the stimulation controller controls the stimulation current amplitude to increase step by step, and the increase amplitude is a set value.

9. The control method according to claim 6, characterized in that: When the blood oxygen saturation signal does not decrease for two consecutive minutes, the stimulation controller controls the electrode sheet A to output electrical stimulation attenuated by one level.

10. The control method according to claim 6, characterized in that: While receiving the blood oxygen saturation signal, the stimulation controller dynamically corrects the output current in combination with the real-time detection result of the electrode contact impedance to ensure the accuracy and safety of the stimulation.

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