Ear vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygenation coordination device and method

Abstract

The application discloses an ear vagus nerve electric stimulation, nasal feeding insulin infusion and oxygen supply synergic device and method, relates to the technical field of medical rehabilitation equipment. A variety of intervention means are integrated in the same control platform, time sequence cooperation, parameter linkage and closed-loop safety control based on physiological feedback are realized. The device comprises a main control module, bilateral ear vagus nerve electric stimulation modules, nasal feeding insulin infusion modules, oxygen supply modules and blood oxygen acquisition and evaluation modules; the electric stimulation modules comprise left and right channels; the blood oxygen acquisition and evaluation modules can calculate blood oxygen saturation according to the pulse wave signals of patients, and evaluate blood oxygen risk grades based on the blood oxygen saturation; the main control module can dynamically adjust the output parameters of the bilateral ear vagus nerve electric stimulation modules, the infusion rates of the nasal feeding insulin infusion modules and the output flow rates of the oxygen supply modules according to preset time sequence cooperation rules and the blood oxygen risk grades; the application also discloses a synergic method based on the above device.

Description

Technical Field

[0001] This application relates to the field of medical rehabilitation equipment technology, and in particular to an integrated neuromodulation, drug infusion and oxygen therapy synergistic device and method for motor function rehabilitation after ischemic stroke. Background Technology

[0002] Ischemic stroke is characterized by a high rate of disability, often leaving patients with residual upper or lower limb motor dysfunction, hemiplegia, abnormal muscle tone, gait disturbances, and decreased fine motor skills. Current rehabilitation methods include motor training, occupational therapy, rehabilitation robot training, functional electrical stimulation, drug therapy, and neuromodulation. In recent years, vagus nerve stimulation (VAS), a non-invasive neuromodulation technique, has been used to stimulate the vagus nerve distribution area in the external ear, influencing brainstem nuclei, autonomic nervous activity, inflammatory regulation, and cortical excitability, providing a new approach to promoting post-stroke neuroplasticity.

[0003] In addition to its role in peripheral glucose metabolism, insulin is also involved in brain energy metabolism, synaptic plasticity, neuroinflammatory regulation, and neurorepair. Insulin administration via nasogastric tube or other intranasal feeding methods is being explored for use as an adjunct to stroke rehabilitation. Furthermore, maintaining adequate oxygenation is crucial for ensuring neurological function recovery, especially for stroke patients who may also experience respiratory dysfunction.

[0004] However, in current clinical practice or research, the ear vagus nerve stimulator, nasogastric feeding device, and oxygen delivery device are usually operated independently, with parameters set separately by the operator. This separate operation has the following technical problems: First, it is difficult to achieve precise temporal coordination of electrical stimulation, insulin delivery, and oxygen delivery, thus failing to leverage the synergistic effect of multimodal intervention; second, it lacks a unified safety feedback mechanism based on the patient's real-time physiological state (especially blood oxygen level), meaning that when the patient experiences risks such as a drop in blood oxygen, it cannot automatically and promptly adjust all intervention parameters, posing a safety hazard; third, most existing ear vagus nerve stimulators provide unilateral or bilateral symmetrical output, making it difficult to flexibly adapt to different stroke lateralities or exercise training tasks.

[0005] Therefore, there is an urgent need for an integrated and intelligent device that combines auricular vagus nerve electrical stimulation, nasal feeding insulin infusion, and oxygen delivery, integrating multiple intervention methods onto a single control platform to achieve time-series coordination, parameter linkage, and closed-loop safety control based on physiological feedback. Summary of the Invention

[0006] The embodiments of this application provide a device and method for coordinating auricular vagus nerve electrical stimulation, nasal feeding insulin infusion, and oxygen delivery, enabling bilateral auricular vagus nerve electrical stimulation, nasal feeding insulin delivery, and oxygen delivery to operate in a coordinated manner under the same main control module, and dynamically adjusting intervention parameters based on blood oxygen risk levels, thereby improving the safety, stability, and individualization of the device during use.

[0007] To achieve the above objectives, in one aspect, embodiments of this application provide a device for coordinated auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery, including a main control module and bilateral auricular vagus nerve electrical stimulation modules, nasogastric insulin infusion modules, oxygen delivery modules, and blood oxygen acquisition and assessment modules, all communicatively connected to the main control module. The bilateral auricular vagus nerve electrical stimulation modules include independently controllable left and right channels, respectively used to connect electrodes fitted to the vagus nerve distribution areas of the patient's left and right ears. The nasogastric insulin infusion module is used to infuse insulin preparations into the patient. The oxygen delivery module delivers oxygen to the patient; the blood oxygen acquisition and assessment module calculates blood oxygen saturation based on the acquired pulse wave signal and assesses the blood oxygen risk level based on the blood oxygen saturation; the main control module dynamically adjusts the output parameters of the bilateral auricular vagus nerve electrical stimulation module, the infusion rate of the nasogastric insulin infusion module, and the output flow rate of the oxygen delivery module according to preset timing coordination rules and blood oxygen risk level; the output parameters include stimulation frequency, stimulation pulse width, stimulation current amplitude, stimulation phase difference, stimulation duty cycle, total stimulation duration, and stimulation interval.

[0008] Furthermore, the bilateral auricular vagus nerve electrical stimulation module can achieve at least one of the following stimulation modes: synchronous output of the left and right channels, alternating output, output with asymmetric parameters, or output with a preset phase difference in time.

[0009] Furthermore, the left channel includes a constant current source circuit, a two-phase pulse polarity switching circuit, and an output isolation and current limiting protection circuit connected in sequence; the main control module is connected to the constant current source circuit through a digital-to-analog converter circuit; the electrode impedance detection circuit is connected to the output terminal of the output isolation and current limiting protection circuit and the main control module respectively, and is used to detect the contact impedance between the electrode and the skin; when the contact impedance exceeds a preset impedance threshold, the main control module cuts off the output of the left channel and issues a prompt; the structure of the right channel is the same as that of the left channel.

[0010] Furthermore, the nasogastric insulin infusion module includes an insulin reservoir unit, a micropump, an infusion tubing, and a pump drive unit; the insulin reservoir unit, the micropump, and the infusion tubing are arranged sequentially along the flow direction of the fluid; the end of the infusion tubing is connected to the patient's nasal cavity or nasogastric interface; both the pump drive unit and the micropump are communicatively connected to the main control module; the main control module controls the start, stop, and speed of the micropump through the pump drive unit.

[0011] Furthermore, the nasogastric insulin infusion module also includes a pressure sensor and a bubble detection unit installed on the insulin delivery line; the pressure sensor is used to monitor the liquid pressure in the insulin delivery line; the bubble detection unit is used to monitor whether there are bubbles in the insulin delivery line; when the liquid pressure exceeds a preset threshold or bubbles are detected, the main control module controls the micro-pump to stop and issues an alarm through the pump drive unit.

[0012] Furthermore, the oxygen delivery module includes an oxygen source interface, an oxygen delivery pipeline, and a proportional valve arranged sequentially along the flow direction of the fluid; the end of the oxygen delivery pipeline is connected to the patient's nasal cavity or nasogastric feeding interface; the proportional valve is communicatively connected to the main control module; the main control module controls the opening degree of the proportional valve based on the comparison result between the blood oxygen saturation value fed back by the blood oxygen acquisition and assessment module and the preset blood oxygen saturation value threshold.

[0013] Furthermore, the blood oxygen acquisition and assessment module includes red and infrared photoplethysmography (PPG) sensors, a motion sensor, and an assessment module. The PPG sensor is used to acquire the patient's pulse wave signal; the motion sensor is used to detect the patient's limb movement or motion artifacts of the sensor itself. The assessment module is configured to: calculate the ratio Rppg based on the red light AC component, red light DC component, infrared light AC component, and infrared light DC component to obtain blood oxygen saturation; simultaneously calculate pulse rate, perfusion index, pulse wave period stability, red / infrared light amplitude stability, and motion artifact intensity; comprehensively calculate the signal quality index (SQI) based on pulse wave amplitude, pulse period stability, perfusion index, red / infrared light ratio stability, motion artifact index, and sensor contact status; when the SQI is lower than a preset threshold, instead of directly using the current blood oxygen value for active parameter adjustment, it enters a conservative safety mode: maintaining or increasing oxygen supply, reducing electrical stimulation intensity, and prompting the user to re-wear the sensor; the blood oxygen risk score is calculated as follows: Rrisk = a1×D1 + a2×D2 + a3×D3 + The formula is: a4×D4 + a5×D5 + a6×D6. Where D1 is the absolute risk factor for blood oxygen saturation, D2 is the decrease in blood oxygen saturation relative to baseline, D3 is the rate of decrease in blood oxygen saturation per unit time, D4 ​​is the duration of oxygen saturation below the threshold, D5 is the time for blood oxygen saturation to recover, and D6 is a combination of abnormal pulse rate and insufficient perfusion. a1 to a6 are weighting coefficients, which can be set according to equipment calibration, clinical protocols, or research protocols. Blood oxygen saturation risk levels are output based on the Rrisk value; these levels include normal, mild risk, moderate risk, and high risk.

[0014] Furthermore, the main control module is configured to: maintain the current electrical stimulation, insulin infusion, and oxygenation parameters when the blood oxygen risk level is normal; increase the oxygen flow rate and decrease the electrical stimulation duty cycle when the blood oxygen risk level is mild; suspend or reduce the insulin infusion rate and decrease the electrical stimulation intensity when the blood oxygen risk level is moderate; and stop insulin infusion and electrical stimulation, maintain or increase oxygenation, and issue an alarm when the blood oxygen risk level is high.

[0015] Furthermore, the main control module is communicatively connected to an external rehabilitation training device; the main control module is configured to receive a motion event trigger signal from the external rehabilitation training device, and to activate or adjust the output of the bilateral auricular vagus nerve electrical stimulation module within a preset time window before, during, or after the motion event.

[0016] On the other hand, embodiments of this application also provide a collaborative method based on a vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery co-contact device, including the following steps: S1, setting a control cycle based on a unified clock, and reading blood oxygen risk level, electrode impedance, infusion pressure, oxygen flow rate, and oxygen pressure in each control cycle to form a collaborative control vector including left / right ear stimulation current, stimulation frequency, stimulation pulse width, insulin infusion rate, and oxygen flow rate; S2, performing baseline assessment: collecting blood oxygen saturation, pulse rate, perfusion index, signal quality index, blood oxygen risk score, electrode impedance, and infusion tubing pressure, and entering the intervention preparation state only when all baseline conditions are met, otherwise prompting for re-wearing or examination; S3, performing pre-oxygenation and pre-stimulation: first administering oxygen at a low flow rate and outputting low-intensity electrical stimulation, if a decrease in blood oxygen or pulse rate occurs... If any abnormality or electrode impedance is detected, the subsequent steps should be paused; S4, Perform coordinated insulin administration and electrical stimulation: Administer insulin via nasogastric tube at the prescribed rate, while simultaneously outputting bilateral auricular vagal nerve electrical stimulation in a synchronous, alternating, or asymmetrical mode and maintaining oxygenation; S5, Perform closed-loop regulation of blood oxygenation: Perform graded responses according to the blood oxygenation risk level: maintain parameters when normal, increase oxygen flow rate and decrease electrical stimulation duty cycle when at mild risk, pause or decrease insulin infusion rate and decrease stimulation intensity when at moderate risk, and stop insulin infusion and electrical stimulation, maintain or increase oxygenation and trigger an alarm when at high risk; S6, Perform recovery observation: After insulin administration is completed, continue to resume oxygenation and low-intensity post-stimulation, and record the lowest blood oxygen saturation, duration of blood oxygenation decline, blood oxygenation recovery time, pulse rate fluctuation, total oxygenation, total stimulation dose, total insulin administration, and abnormal events.

[0017] This application has the following advantages over the prior art: 1. The auricular vagus nerve electrical stimulation, nasal feeding insulin infusion and oxygen supply coordination device in this application embodiment controls bilateral auricular vagus nerve electrical stimulation, insulin infusion and oxygen supply in a unified manner through the main control module, realizing the precise coordination of multimodal intervention in time sequence, and maximizing the synergistic effect of different treatment methods.

[0018] 2. The auricular vagus nerve electrical stimulation, nasal feeding insulin infusion and oxygen delivery coordination device of this application introduces a closed-loop feedback mechanism based on real-time blood oxygen saturation, which can automatically and hierarchically adjust various intervention parameters according to the patient's physiological state, significantly improving the safety and individualization of the treatment process.

[0019] 3. The auricular vagus nerve electrical stimulation, nasal feeding insulin infusion and oxygenation coordination device in the embodiments of this application supports independent, asymmetrical and temporally differentiated stimulation of the bilateral auricular vagus nerve, which can be flexibly adapted to different stroke lateralization and rehabilitation training tasks, and enhances the precision of neural modulation.

[0020] 4. The auricular vagus nerve electrical stimulation, nasal feeding insulin infusion and oxygen delivery coordination device in this application embodiment can receive the movement trigger signal of external rehabilitation training equipment, realize the precise time matching of nerve stimulation and active movement intention, and is expected to further improve the rehabilitation effect. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a structural block diagram of the device for coordinating auricular vagus nerve electrical stimulation, nasal feeding insulin infusion, and oxygen delivery according to an embodiment of this application.

[0023] Figure 2 This is a circuit diagram of the bilateral auricular vagus nerve electrical stimulation module in the auricular vagus nerve electrical stimulation, nasal feeding insulin infusion and oxygenation coordination device of this application embodiment.

[0024] Figure 3 This is a schematic diagram of the nasogastric insulin infusion module in the auricular vagus nerve electrical stimulation, nasogastric insulin infusion and oxygenation coordination device of this application embodiment.

[0025] Figure 4 This is a schematic cross-sectional view of the double-lumen nasal tube in the vagus nerve electrical stimulation, nasal feeding insulin infusion and oxygen delivery coordination device of the present application embodiment.

[0026] Figure 5This is a schematic diagram of the parallel independent nasal tube structure in the vagus nerve electrical stimulation, nasogastric insulin infusion and oxygen delivery coordination device of this application embodiment.

[0027] Figure 6 This is a flowchart illustrating the blood oxygen acquisition and assessment process of the vagus nerve electrical stimulation, nasal feeding insulin infusion, and oxygen delivery coordination device according to an embodiment of this application.

[0028] Figure 7 This is a diagram showing the timing coordination of electrical stimulation, insulin infusion, and oxygen delivery in the auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery coordination device according to an embodiment of this application. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, they can refer to fixed connections, detachable connections, or integral connections; those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" can explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0033] The existing vagus nerve stimulation devices, nasogastric feeding devices, and oxygen delivery devices lack unified control, making it difficult to achieve precise timing coordination of electrical stimulation, insulin delivery, and oxygen therapy. Furthermore, they lack sufficient left-right differential control for bilateral ear stimulation, making it difficult to flexibly adapt to different stroke sides or exercise training tasks. In addition, blood oxygen monitoring is mostly limited to display or alarm levels, failing to form a closed-loop control linked to stimulation, infusion, and oxygen delivery parameters.

[0034] The present invention aims to provide an integrated device for coordinating bilateral auricular vagus nerve electrical stimulation, nasal feeding insulin infusion, and oxygenation, enabling bilateral auricular vagus nerve electrical stimulation, nasal feeding insulin administration, and oxygenation to operate in a coordinated manner under the same main control module, and dynamically adjusting intervention parameters based on blood oxygen risk levels, thereby improving the safety, stability, and individualization of the device during use.

[0035] Reference Figures 1 to 5 The device for coordinating auricular vagus nerve electrical stimulation, nasal feeding insulin infusion, and oxygen delivery includes a main control module, a bilateral auricular vagus nerve electrical stimulation module, a nasal feeding insulin infusion module, an oxygen delivery module, a blood oxygen acquisition and assessment module, a safety monitoring module, a data storage and communication module, and a human-computer interaction module.

[0036] The main control module, as the core of the system, is responsible for reading prescription parameters and sensor data, and executing control commands to the electrical stimulation module, micro-infusion pump and oxygen valve.

[0037] Specifically, refer to Figure 1 The main control module, as the core control unit of the entire device, uses the STM32L4 series embedded processing chip, which has efficient equivalent computing capabilities and rich interface resources. Through multiple interfaces such as SPI, I²C, UART, ADC, PWM and GPIO, it establishes connections with the bilateral auricular vagus nerve electrical stimulation module, the micro-pump drive circuit of the nasogastric insulin infusion module, the pressure sensor, the blood oxygen simulation front end of the oxygen supply module, the oxygen pressure sensor, the oxygen flow sensor, the blood oxygen acquisition and evaluation module, the safety monitoring module, the data storage and communication module, and the human-computer interaction module, to realize bidirectional signal transmission and command issuance.

[0038] In a preferred embodiment, the main control module also integrates a low-power microcontroller, external Flash memory, real-time clock, watchdog circuit, battery power detection circuit, charging management circuit, and hardware emergency stop input. The functions and calculation logic of each circuit are as follows: 1. External Flash memory: Used to expand data storage capacity, store patient treatment data and parameter configurations. The storage capacity is set according to clinical needs, ensuring that at least 30 days of continuous treatment data can be stored.

[0039] 2. Real-time clock: Used for precise timing to ensure the timely triggering of the treatment process. The timing accuracy is ≤1s / 24h. It communicates with the main control chip through the I²C interface to achieve time calibration and synchronization.

[0040] 3. Watchdog circuit: Used to prevent program crashes and improve system stability. The watchdog timeout is set to 100ms. If the main control chip fails to feed the watchdog on time, the system will be automatically reset.

[0041] 4. Battery power detection circuit: Real-time acquisition of battery voltage (range 3.0~4.2V), conversion into digital signal via ADC, and calculation of remaining power based on battery discharge curve. The calculation formula is: Remaining power (%) = (current voltage - 3.0V) / (4.2V - 3.0V) × 100%. An alarm is triggered when the power is lower than a preset threshold (e.g., 20%).

[0042] 5. Charging management circuit: Adopts constant current and constant voltage charging mode to ensure safe battery charging. The charging current is set to 0.5C~1C through circuit calculation (C is the battery capacity). During the constant current stage, the charging current remains constant. When the battery voltage reaches 4.2V, it switches to the constant voltage stage. When the charging current gradually decreases to below 100mA, charging stops.

[0043] 6. Hardware emergency stop input: It adopts an independent hardware circuit design with higher priority than software control. When the emergency stop button is pressed, all module outputs can be cut off immediately, triggering the relay to disconnect the stimulation, infusion, and oxygenation circuits to ensure patient safety.

[0044] The human-machine interaction and communication module includes buttons, a touchscreen, a buzzer, and indicator lights. These are used by medical staff to set stimulation protocols, insulin infusion protocols, oxygen delivery protocols, and alarm thresholds, while also providing feedback on the device's operating status. The buzzer and indicator lights employ a tiered alarm design, with different sound and light combinations corresponding to different fault types (such as poor electrode contact, tubing blockage, and insufficient oxygen) for easy and rapid identification.

[0045] The communication module employs multiple communication methods including Bluetooth, Wi-Fi, and USB. Bluetooth is used for short-range data interaction with medical staff's mobile terminals, with a communication rate set at 115200bps. Wi-Fi is used to access the hospital's local area network, using the 802.11b / g / n protocol to achieve data synchronization with rehabilitation training equipment, host computers, electronic medical record systems, or research data platforms. The USB interface is used for local data export and device firmware upgrades, with a data transmission rate ≥480Mbps, ensuring the stability and real-time performance of data transmission.

[0046] The bilateral auricular vagus nerve electrical stimulation module includes independently controllable left and right channels, used to connect electrodes to the vagus nerve distribution areas of the patient's left and right ears, respectively. The electrical stimulation output employs a constant-current biphasic pulse structure to reduce electrode polarization and tissue charge accumulation. The module can achieve synchronous stimulation of both ears, alternating stimulation of both ears, left-ear-preferred stimulation, right-ear-preferred stimulation, or asymmetrical stimulation of both ears. Stimulation parameters include stimulation frequency, pulse width, current amplitude, phase difference, duty cycle, total stimulation duration, and interval.

[0047] Specifically, refer to Figure 2 The bilateral auricular vagus nerve stimulation module includes a digital-to-analog converter circuit, a left channel, and a right channel. The left and right channels have the same structure, both including a constant current source circuit, a biphasic pulse polarity switching circuit, an output isolation and current limiting protection circuit, and an electrode impedance detection circuit. The electrical stimulation generation and circuit signal flow are as follows: 1. Electrical Stimulation Generation Process: The main control module generates a timed trigger signal (frequency consistent with the stimulation frequency) through the GPIO interface according to the preset prescription parameters, triggering the digital-to-analog converter circuit to work. The digital-to-analog converter uses an AD5693R device, which receives the control command from the main control module and converts the 16-bit digital signal into the corresponding stimulation amplitude control voltage (voltage range 0~5V). The calculation basis of this control voltage is the ratio of the target stimulation current to the gain of the constant current source circuit, that is, control voltage U=I×R (I is the target stimulation current, R is the feedback resistor of the constant current source, with a value of 1kΩ~10kΩ, set according to the stimulation current range).

[0048] 2. Constant current source circuit: Generates a stable target current based on the input control voltage. Adopts an improved Howland constant current source structure. The operational amplifier uses the AD8606 low-noise device to ensure the stability of the output current. The current ripple is controlled within ±1%. The constant current output range is 0.1mA~10mA, which meets the stimulation parameter requirements.

[0049] 3. Dual-phase pulse polarity switching circuit: Based on the ADG5412 low on-resistance analog switch array, the circuit controls the on and off of the analog switches according to the PWM signal of the main control module to achieve alternation of positive and negative polarities. The switching time is ≤10μs, avoiding the generation of peak current during polarity switching. The peak current is controlled within 10% of the target current.

[0050] 4. Output Isolation and Current Limiting Protection Circuit: An ADuM2201 digital isolator is used to achieve electrical isolation between the main control circuit and the stimulation output circuit. The isolation voltage is ≥2500Vrms, meeting medical electrical safety requirements. A current-limiting resistor is also included, with its value calculated based on the maximum stimulation current: R=U / I (U is the supply voltage, taken as 12V, I is the maximum stimulation current 10mA), resulting in a resistance of 1.2kΩ. An SMBJ6.5CA transient suppressor is configured to suppress surge voltage and protect the electrodes and patient. A 1μF DC blocking capacitor is provided to block the DC component and prevent DC current from stimulating the skin and causing damage. An electronic switch is added, controlled by the GPIO interface of the main control module, which can quickly cut off the stimulation output in case of abnormality.

[0051] The stimulation parameters can be set as follows: stimulation frequency 1Hz~100Hz, preferably 5Hz~30Hz; pulse width 50μs~1000μs, preferably 100μs~500μs; stimulation current 0.1mA~10mA, preferably 0.5mA~6mA; duty cycle 1%~80%; left and right ear phase difference 0ms~5000ms. The main control module can dynamically adjust the above parameters according to user tolerance, electrode impedance, blood oxygen risk level, and rehabilitation training tasks. The circuit logic for parameter adjustment is as follows: the main control module collects feedback signals such as electrode impedance and blood oxygen saturation through ADC, processes them through RC low-pass filtering (cutoff frequency 10Hz) and operational amplifier amplification (amplification factor 10 times), substitutes them into the preset algorithm to calculate the optimal parameters, and then sends parameter commands to the digital-to-analog converter through the I²C interface to adjust the stimulation amplitude control voltage, thereby changing the constant current source output current and realizing the dynamic control of stimulation parameters.

[0052] The electrode impedance detection circuit applies a low-amplitude detection signal (amplitude ≤ 0.05mA, frequency 1kHz) to the electrodes before stimulation and during stimulation intervals (every 100ms). This detection signal is generated by the main control module through a constant current source circuit controlled by a PWM signal. The response voltage across the electrodes is acquired via an ADC (12-bit acquisition accuracy). The skin-electrode contact impedance is calculated according to Ohm's law R=U / I, where U is the acquired response voltage and I is the detection signal current. When the contact impedance exceeds the preset range (500-5000Ω), the main control module immediately cuts off the stimulation output circuit on the corresponding ear side via the GPIO interface and sends a command to the human-machine interface module to prompt medical staff to re-wear the electrodes.

[0053] Reference Figure 3 The nasogastric insulin infusion module includes an insulin reservoir, a micro-pump, a pump drive circuit, infusion tubing, a nasogastric interface, a pressure sensor, a bubble detection unit, and an anti-reflux valve. The main control module controls the start time, infusion rate, single dose, total dose, and pause / recovery strategy of insulin administration based on a preset prescription and blood oxygen risk level.

[0054] Specifically, the micro-infusion pump uses a stepper motor to drive it, and the pump drive circuit uses a TMC2209 motor driver chip. The main control module sends pulse signals through the GPIO interface to control the motor speed, thereby controlling the infusion rate. The calculation logic for the infusion rate is as follows: based on the preset infusion dose and infusion time, the required motor speed n = (V × 60) / (π × D × L) is calculated (V is the infusion rate, in ml / h; D is the pump tube inner diameter, in cm; L is the propulsion length per revolution of the motor, in cm / r). The motor drive circuit outputs the corresponding current (0.5A~2A) according to the speed command to drive the motor and ensure that the infusion accuracy error does not exceed ±5%.

[0055] A pressure sensor is installed at the pump outlet to detect pipe blockage, kinking, detachment, or abnormal pressure fluctuations. A piezoresistive pressure sensor with a range of 0~100kPa is selected to convert the pressure signal into a voltage signal of 0~3.3V. After being acquired by an ADC (acquisition frequency 10Hz), the main control module converts the voltage signal into the actual pressure value through a calibration algorithm (linear calibration, y=kx+b, where k is the calibration coefficient and b is the offset). When the pressure value exceeds the preset threshold (e.g., 50kPa), it is determined that the pipe is blocked, the pump operation is stopped immediately, and an audible and visual alarm is triggered.

[0056] The insulin preparation reservoir unit uses a disposable reservoir structure. An anti-backflow valve is installed between the reservoir unit and the infusion tubing to prevent fluid from flowing back into the nasal cavity or tubing. The bubble detection unit uses a photoelectric detection circuit, consisting of an infrared emitter and receiver. The infrared emitter outputs infrared light of a fixed amplitude. When there is an air bubble in the tubing, the transmittance of the infrared light changes, and the voltage signal output by the receiver changes accordingly (change ≥ 0.5V). The main control module acquires this voltage signal via an ADC and compares it with a preset threshold to determine the presence of air bubbles. When air bubbles, blockages, or insufficient reservoir fluid are detected, the main control module stops the pump and issues an alarm.

[0057] The oxygen delivery module includes an oxygen source interface, a pressure reducing unit, a proportional valve, and an oxygen delivery pipeline arranged sequentially along the fluid flow direction. The oxygen delivery pipeline is equipped with an oxygen flow sensor, an oxygen pressure sensor, an oxygen concentration detection unit, and a pressure relief valve. The oxygen delivery module can perform pre-oxygenation, synergistic oxygenation, and recovery oxygenation before, during, and after insulin administration. The oxygen flow rate is dynamically adjusted based on the blood oxygen risk level, the rate of decrease in blood oxygen, and the blood oxygen recovery time.

[0058] The oxygen flow sensor uses a thermal mass flow sensor, whose output signal is an analog voltage of 0~5V, linearly related to the oxygen flow rate. After being acquired by an ADC, the main control module converts the voltage signal into the actual flow rate value through a linear calibration algorithm (y=0.2x, where x is the voltage value and y is the flow rate value in L / min). The oxygen delivery flow rate can be set from 0.1L / min to 10L / min, preferably from 0.5L / min to 5L / min. The specific value is determined by the prescription parameters and the blood oxygen risk level. The flow rate adjustment logic is as follows: the main control module controls the opening of the proportional valve through a PWM signal (the PWM duty cycle is linearly related to the valve opening) based on the blood oxygen saturation value fed back by the blood oxygen acquisition and assessment module, adjusting the oxygen output flow rate to ensure that the blood oxygen saturation is maintained above 95%.

[0059] The oxygen pressure sensor is used to detect the pressure in the oxygen pipeline. The range is 0~1MPa. When the pressure exceeds the normal range of 0.1~0.3MPa, the pressure relief valve will automatically open to release pressure, and the main control module will trigger an alarm.

[0060] Reference Figure 4 The nasogastric insulin infusion module and oxygen delivery module are preferably connected to an integrated dual-lumen nasal cannula. The first lumen is used for insulin administration, and the second lumen is used for oxygen delivery. A physical isolation structure exists between the two lumen to prevent fluctuations in oxygen flow from affecting the insulin dosage. The design of the isolation structure must meet the requirements of tubing resistance calculation, using the formula ΔP=8μLQ / (πr). 4 (μ is the fluid viscosity, L is the pipe length, Q is the flow rate, and r is the pipe inner diameter) Calculate to ensure that the insulin infusion resistance is ≤5 kPa / mL·min and the oxygen delivery resistance is ≤2 kPa / L·min.

[0061] In another embodiment, refer to Figure 5 The insulin nasal feeding tubing and oxygen nasal cannula are parallel and independent structures, and their relative positions are maintained by a flexible fixing frame. The elastic coefficient of the fixing frame is calculated and set to 10~20N / m to ensure comfortable wearing and prevent displacement.

[0062] The blood oxygen acquisition and assessment module collects red and infrared pulse wave signals and, in conjunction with the output of the motion sensor, calculates blood oxygen saturation, pulse rate, perfusion index, motion artifact index, and signal quality index. The main control module outputs normal, mild, moderate, and high-risk levels based on the blood oxygen risk score, and adjusts the electrical stimulation intensity, stimulation duty cycle, insulin infusion rate, and oxygen flow rate accordingly.

[0063] Reference Figure 6 The blood oxygen acquisition and assessment module includes a photoplethysmography (PPG) sensor, a motion sensor, and an assessment module.

[0064] The photoplethysmography (PPG) sensor acquires PPG signals using red and infrared photoplethysmography (PPG) sensors. The PPG sensor can be positioned on the finger, forehead, earlobe, or wrist. Considering that electrical stimulation of the ear may cause local electromagnetic or motion artifacts, it is preferable to position the PPG sensor on the finger or forehead.

[0065] Motion sensors, which can employ triaxial accelerometers or six-axis inertial measurement units, are used to identify limb movements, sensor loosening, and artifacts caused by exercise training.

[0066] The blood oxygen acquisition and assessment module calculates the ratio Rppg based on the red light AC component, red light DC component, infrared light AC component, and infrared light DC component, and obtains the blood oxygen saturation accordingly.

[0067] The evaluation module simultaneously calculates pulse rate, perfusion index, pulse wave period stability, red / infrared light amplitude stability, and motion artifact intensity.

[0068] The Signal Quality Index (SQI) can be calculated by considering the following factors: pulse amplitude, pulse cycle stability, perfusion index, red / infrared light ratio stability, motion artifact index, and sensor contact status.

[0069] When the SQI is lower than the preset threshold, the assessment module outputs a low signal quality flag to the main control module. Instead of directly using the current blood oxygen value for active parameter adjustment, the main control module controls the device to enter a conservative safety mode, maintaining or increasing oxygen supply, reducing electrical stimulation intensity, and prompting the user to re-wear the sensor.

[0070] like Figure 7 As shown, the blood oxygen risk score (Rrisk) can be calculated as follows for a complete coordinated process of electrical stimulation, insulin infusion, and oxygenation: Rrisk = a1×D1 + a2×D2 + a3×D3 + a4×D4 + a5×D5 + a6×D6.

[0071] Wherein, D1 is the absolute risk item for blood oxygenation, D2 is the decrease in blood oxygenation relative to baseline, D3 is the rate of decrease in blood oxygenation per unit time, D4 ​​is the duration of being below the threshold, D5 is the time for blood oxygenation to recover, and D6 is a combination of abnormal pulse rate and insufficient perfusion. a1 to a6 are weighting coefficients, which can be set according to equipment calibration, clinical protocol, or research protocol.

[0072] Based on the Rrisk value, the system outputs a normal, mild, moderate, or high-risk level. A normal level corresponds to maintaining the current parameters; mild risk corresponds to increasing oxygen flow and decreasing the stimulation duty cycle; moderate risk corresponds to pausing or slowing insulin infusion and reducing stimulation intensity; and high risk corresponds to stopping infusion and stimulation, maintaining or increasing oxygen supply, and triggering an alarm.

[0073] The safety monitoring module integrates a blood oxygen acquisition and assessment module, a pressure sensor, an oxygen flow sensor, an oxygen pressure sensor, an electrode impedance detection circuit, etc., to collect patient physiological parameters and device operating parameters in real time, with a acquisition frequency of 1 time / second.

[0074] The main control module analyzes the collected data through a preset safety algorithm. When abnormal parameters occur (such as blood oxygen saturation <90%, abnormal electrode impedance, excessively high tubing pressure, or abnormal oxygen flow), it immediately triggers an alarm and takes corresponding protective measures (such as stopping stimulation, pausing infusion, or cutting off oxygen supply) to ensure treatment safety.

[0075] The data recording module is connected to the external Flash memory of the main control module to record all parameters during the treatment process in real time, including stimulation parameters, insulin infusion parameters, oxygenation parameters, patient physiological parameters, alarm records, etc. The data can be exported or uploaded to relevant systems through the communication module, which facilitates subsequent disease analysis and treatment plan optimization.

[0076] On the other hand, refer to Figure 7 This application also provides a collaborative method based on a device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery. This method uses a unified clock of the main control module as a reference and divides bilateral auricular vagus nerve electrical stimulation, nasogastric insulin delivery, oxygen delivery, and blood oxygen assessment into a baseline assessment stage, a pre-oxygenation and pre-stimulation stage, an insulin delivery and electrical stimulation coordination stage, a blood oxygen closed-loop regulation stage, and a recovery observation stage. The control cycle is Δtc, which can be set to 0.5s to 5s, preferably 1s. Within each control cycle, the main control module reads the blood oxygen risk level, electrode impedance, infusion pressure, oxygen flow rate, oxygen pressure, and exercise task trigger signal, and forms a collaborative control vector.

[0077] in, , The stimulation currents were applied to the left and right ears, respectively. , The stimulation frequencies for the left and right ears are respectively; , The pulse widths for stimulation of the left and right ears are respectively; Insulin infusion rate; Oxygen flow rate, This is the discrete control cycle number.

[0078] After the device is started, the main control module first collects the subject's baseline blood oxygen saturation, pulse rate, perfusion index, motion artifacts, electrode impedance, nasogastric tube pressure, oxygen supply pressure, and oxygen flow rate zero point. Baseline validity is determined by the following conditions:

[0079] in, Blood oxygen saturation; Pulse rate; For perfusion index; Signal quality index; Blood oxygen risk score; Electrode impedance; This refers to the pressure in the nasogastric feeding line. If any condition is not met, the main control module will not proceed to the next intervention stage and will prompt the user to re-wear the electrodes, check the nasogastric feeding line, or check the oxygen source.

[0080] The system enters the intervention preparation state only when the electrode contact, tubing status, oxygenation status, and blood oxygenation signal quality all meet the requirements.

[0081] During the pre-oxygenation and pre-stimulation phase, the oxygen delivery module first provides oxygen at a low flow rate, while the bilateral auricular vagus nerve electrical stimulation module outputs stimulation at a low intensity to assess the subject's immediate response to electrical stimulation and oxygen delivery. The pre-stimulation frequency can be set to 1Hz–30Hz, the current amplitude can be set to 10%–50% of the target stimulation current, and the pre-stimulation duration can be set to 30s–10min.

[0082] If a decrease in blood oxygenation, abnormal pulse rate, or abnormal electrode impedance occurs during this phase, the system will pause the insulin administration phase.

[0083] During the insulin delivery and electrical stimulation synergy phase, the main control module controls the micro-infusion pump to deliver insulin via the nasogastric tube at a set rate. Simultaneously, it controls the bilateral auricular vagus nerve electrical stimulation modules to output stimulation in synchronous, alternating, or asymmetrical modes, while maintaining synergistic oxygen delivery. The insulin infusion rate and total volume are limited by prescription parameters. The device only performs pump control operations within the prescription range and stops infusion when the total volume limit is reached or an abnormality occurs.

[0084] When the device is connected to a rehabilitation robot, electromyography triggering device, motion capture device, or training software, the main control module can receive motion task triggering signals and output auricular vagus nerve stimulation within a preset time window before and after motion events such as grasping, wrist extension, elbow extension, ankle dorsiflexion, and gait training, thereby achieving time matching between neural regulation and motion training tasks.

[0085] During the closed-loop blood oxygen regulation phase, the main control module reads the blood oxygen risk level every preset cycle.

[0086] When the risk level is normal, the system maintains the current electrical stimulation, insulin infusion, and oxygenation parameters.

[0087] When the risk level is mild, the system increases oxygen flow and reduces electrical stimulation duty cycle.

[0088] When the risk level is moderate, the system pauses or reduces the insulin infusion rate and decreases the stimulation intensity.

[0089] When the risk level is high, the system stops insulin infusion and electrical stimulation, maintains or increases oxygen supply, and issues an audible and visual alarm.

[0090] During the recovery observation phase, after insulin administration, the system continued to perform pre-set recovery oxygen administration and low-intensity post-stimulation, and recorded the lowest blood oxygen saturation, duration of blood oxygen decline, blood oxygen recovery time, pulse rate fluctuations, total oxygen administration, total stimulation dose, total insulin administration, and abnormal events.

[0091] In one implementation, the main control module calculates the effective stimulation charge amount per cycle for the left and right ears, respectively.

[0092] Effective stimulation charge in a single cycle in the left ear The effective stimulation charge in a single cycle of the right ear is determined by the positive and negative pulse charge in the left ear. It is determined by the positive and negative pulse charge quantities of the right ear.

[0093] For a charge-balanced biphasic pulse, the effective stimulation charge amount for a single cycle in the left ear satisfies... The effective stimulation charge in a single cycle of the right ear meets the requirements. In the first Within each stimulation phase, the stimulation dose for the left ear phase is:

[0094] The stimulation dose for the right ear stage is:

[0095] The main control module is based on , and the dose difference coefficient between the left and right ears Determine whether bilateral vagus nerve stimulation meets the prescription restrictions, and reduce the stimulation current, stimulation duty cycle, or pause stimulation output when the preset dose threshold is exceeded or the blood oxygen risk level increases.

[0096] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A device for coordinating vagal nerve electrical stimulation, nasal feeding insulin infusion, and oxygen delivery, characterized in that, It includes a main control module and a bilateral auricular vagus nerve electrical stimulation module, a nasogastric insulin infusion module, an oxygen delivery module, and a blood oxygen acquisition and assessment module that are connected to the main control module. The bilateral auricular vagus nerve electrical stimulation module includes independently controllable left and right channels, which are used to connect electrodes that fit into the vagus nerve distribution areas of the patient's left and right ears, respectively. The nasogastric insulin infusion module is used to infuse insulin preparations into patients; The oxygen delivery module is used to deliver oxygen to the patient; The blood oxygen acquisition and assessment module can calculate blood oxygen saturation based on the acquired pulse wave signal of the patient, and assess the blood oxygen risk level based on the blood oxygen saturation. The main control module can dynamically adjust the output parameters of the bilateral auricular vagus nerve electrical stimulation module, the infusion rate of the nasogastric insulin infusion module, and the output flow rate of the oxygen delivery module according to the preset timing coordination rules and blood oxygen risk level. The output parameters include stimulation frequency, stimulation pulse width, stimulation current amplitude, stimulation phase difference, stimulation duty cycle, total stimulation duration, and stimulation interval.

2. The device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery according to claim 1, characterized in that, The bilateral auricular vagus nerve electrical stimulation module can achieve at least one of the following stimulation modes: synchronous output of the left and right channels, alternating output, output with asymmetric parameters, or output with a preset phase difference in time.

3. The device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery according to claim 2, characterized in that, The left channel includes a constant current source circuit, a two-phase pulse polarity switching circuit, and an output isolation and current limiting protection circuit connected in sequence; the main control module is connected to the constant current source circuit through a digital-to-analog converter circuit; the electrode impedance detection circuit is connected to the output terminal of the output isolation and current limiting protection circuit and the main control module respectively, and is used to detect the contact impedance between the electrode and the skin; when the contact impedance exceeds the preset impedance threshold, the main control module cuts off the output of the left channel and issues a prompt; the structure of the right channel is the same as that of the left channel.

4. The device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery according to claim 1, characterized in that, The nasogastric insulin infusion module includes an insulin reservoir, a micropump, an infusion tubing, and a pump drive unit. The insulin reservoir, micropump, and infusion tubing are arranged sequentially along the flow direction of the fluid. The end of the infusion tubing is connected to the patient's nasal cavity or nasogastric feeding port. Both the pump drive unit and the micropump are communicatively connected to the main control module. The main control module controls the start, stop, and speed of the micropump through the pump drive unit.

5. The device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery according to claim 4, characterized in that, The nasogastric insulin infusion module also includes a pressure sensor and a bubble detection unit installed on the insulin delivery line; the pressure sensor is used to monitor the liquid pressure in the insulin delivery line; the bubble detection unit is used to monitor whether there are bubbles in the insulin delivery line; when the liquid pressure exceeds a preset threshold or bubbles are detected, the main control module controls the micro-pump to stop and issue an alarm through the pump drive unit.

6. The device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery according to claim 1, characterized in that, The oxygen delivery module includes an oxygen source interface, an oxygen delivery pipeline, and a proportional valve arranged sequentially along the flow direction of the fluid; the end of the oxygen delivery pipeline is connected to the patient's nasal cavity or nasogastric feeding interface; the proportional valve is communicatively connected to the main control module. The main control module controls the opening degree of the proportional valve based on the comparison result between the blood oxygen saturation value fed back by the blood oxygen acquisition and assessment module and the preset blood oxygen saturation value threshold.

7. The device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery according to claim 6, characterized in that, The blood oxygen acquisition and assessment module includes red light and infrared photoplethysmography (PPG) sensors, a motion sensor, and an assessment module; the PPG sensors are used to acquire the patient's pulse wave signal; the motion sensor is used to detect the patient's limb movement or motion artifacts of the sensor itself. The evaluation module is configured as follows: The ratio Rppg is calculated based on the red light AC component, red light DC component, infrared light AC component, and infrared light DC component to obtain blood oxygen saturation; at the same time, pulse rate, perfusion index, pulse wave period stability, red light / infrared light amplitude stability, and motion artifact intensity are also calculated. The signal quality index (SQI) is calculated by combining pulse wave amplitude, pulse cycle stability, perfusion index, red / infrared light ratio stability, motion artifact index, and sensor contact status. When the SQI is lower than the preset threshold, the current blood oxygen value is not used for active parameter adjustment. Instead, a conservative safety mode is entered: oxygen supply is maintained or increased, electrical stimulation intensity is reduced, and the sensor is prompted to be worn again. Calculate the blood oxygen risk score as follows: Rrisk = a1×D1 + a2×D2 + a3×D3 + a4×D4 + a5×D5 + a6×D6. Among them, D1 is the absolute risk item of blood oxygen, D2 is the decrease in blood oxygen relative to baseline, D3 is the rate of decrease in blood oxygen per unit time, D4 ​​is the duration of being below the threshold, D5 is the blood oxygen recovery time, and D6 is the combined item of abnormal pulse rate and insufficient perfusion; a1 to a6 are weighting coefficients, which can be set according to equipment calibration, clinical protocol or research protocol. The blood oxygen risk level is output based on the Rrisk value; the blood oxygen risk level includes normal, mild risk, moderate risk and high risk.

8. The device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery according to claim 7, characterized in that, The main control module is configured as follows: When the blood oxygen risk level is normal, maintain the current electrical stimulation, insulin infusion, and oxygenation parameters; When the blood oxygen risk level is mild, increase the oxygen flow rate and decrease the electrical stimulation duty cycle; When the blood oxygen risk level is moderate, pause or reduce the insulin infusion rate and reduce the electrical stimulation intensity. When the blood oxygen risk level is high, stop insulin infusion and electrical stimulation, maintain or increase oxygen supply and issue an alarm.

9. The device for coordinating auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery according to claim 1, characterized in that, The main control module is communicatively connected to the external rehabilitation training equipment. The main control module is configured to receive motion event trigger signals from the external rehabilitation training equipment and, within a preset time window before, during, or after the occurrence of a motion event, activate or adjust the output of the bilateral auricular vagus nerve electrical stimulation module.

10. A synergistic method based on the auricular vagus nerve electrical stimulation, nasogastric insulin infusion, and oxygen delivery synergistic device according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Set the control cycle based on a unified clock, and read the blood oxygen risk level, electrode impedance, infusion pressure, oxygen flow rate and oxygen pressure in each control cycle to form a coordinated control vector including left / right ear stimulation current, stimulation frequency, stimulation pulse width, insulin infusion rate and oxygen flow rate. S2. Perform baseline assessment: Collect blood oxygen saturation, pulse rate, perfusion index, signal quality index, blood oxygen risk score, electrode impedance, and infusion tubing pressure. Enter the intervention preparation state only when all baseline conditions are met; otherwise, prompt for re-wearing or inspection. S3. Perform pre-oxygenation and pre-stimulation: First, administer oxygen at a low flow rate and output low-intensity electrical stimulation. If blood oxygenation decreases, pulse rate becomes abnormal, or electrode impedance becomes abnormal, then pause the subsequent steps. S4. Perform coordinated insulin administration and electrical stimulation: Administer insulin via nasogastric tube at the prescribed rate, while simultaneously outputting bilateral auricular vagus nerve electrical stimulation in a synchronous, alternating, or asymmetrical mode and maintaining oxygen supply. S5. Perform closed-loop regulation of blood oxygenation: respond in stages according to the level of blood oxygenation risk: maintain parameters when normal, increase oxygen flow and reduce electrical stimulation duty cycle when at mild risk, suspend or reduce insulin infusion rate and reduce stimulation intensity when at moderate risk, and stop insulin infusion and electrical stimulation, maintain or increase oxygenation and alarm when at high risk. S6. Perform recovery observation: After insulin administration is completed, continue to administer oxygen and low-intensity post-stimulation, and record the lowest blood oxygen saturation, duration of blood oxygen decline, blood oxygen recovery time, pulse rate fluctuation, total oxygen administration, total stimulation dose, total insulin administration, and abnormal events.

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