An insulin automatic injection device for monitoring blood glucose and blood potassium and a control method thereof

Abstract

This invention belongs to the field of medical device technology, specifically an automated insulin injection device and control method for monitoring blood glucose and potassium levels. It simultaneously acquires tissue fluid glucose and potassium ion concentrations via a flexible dual-mode sensor patch. A lightweight neural network model is used to correct the potassium ion concentration using data such as body temperature and heart rate variability to estimate serum potassium concentration. Automated insulin injection is only permitted when blood glucose is above a threshold and serum potassium is within a safe range (3.5–5.0 mmol / L). If serum potassium is too high (>5.5 mmol / L), injection is prohibited and an alarm is triggered; if it is too low (<3.0 mmol / L), the single dose is limited. The device is integrated into a curved, waist-worn housing, containing a miniature insulin pump, controller, and tubing, and features device status self-checking and multi-channel alarm functions. This invention significantly improves the safety of closed-loop insulin therapy, and is particularly suitable for high-risk individuals such as those with renal insufficiency.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular to an automatic insulin injection device and control method for monitoring blood glucose and blood potassium. Background Technology

[0002] Wearable blood glucose monitoring and automated insulin delivery devices represent a significant technological direction in diabetes management. A typical example is the "artificial pancreas" system, which typically consists of a continuous glucose monitoring (CGM) module, an insulin pump, and a control algorithm. Its purpose is to automatically adjust insulin infusion through closed-loop feedback to maintain blood glucose levels within a target range. In recent years, with advancements in microelectronics, biosensing, and control theory, these devices have gradually evolved from open-loop assistance to fully automated closed-loop systems, significantly reducing the burden of self-management for patients.

[0003] The design logic of all current commercial closed-loop insulin systems is based on a simplified model of "high blood sugar = need for insulin". Their control algorithms only receive the tissue fluid glucose concentration signal from the continuous glucose monitoring (CGM) module, calculate the required insulin dose through a predictive model or PID controller, and drive the pump to execute the infusion. This paradigm stems from the early artificial pancreas research's focus on the core objective of "glycemic control," neglecting to incorporate electrolyte disturbances caused by common diabetic complications—such as renal insufficiency, autonomic neuropathy, or drug interactions—into the decision-making framework. The fundamental reason is: (1) There has been a lack of mature sensor solutions for continuous, reliable and minimally invasive monitoring of serum potassium. Ion selective electrodes (ISEs) are prone to drift in tissue fluid and have a short lifespan. Furthermore, the correlation between tissue fluid K⁺ and serum K⁺ is affected by multiple factors such as local blood flow, pH, and temperature. (2) Traditional views hold that blood glucose is the only metabolic indicator that needs to be dynamically regulated, ignoring the significant physiological effects of insulin on electrolytes (especially potassium).

[0004] If this problem is not addressed promptly, insulin not only promotes glucose entry into cells but also activates Na⁺ / K⁺-ATPase, causing K⁺ to shift from the extracellular space to the intracellular space, thereby rapidly lowering serum potassium levels. This effect is particularly dangerous in patients with hyperkalemia. Summary of the Invention

[0005] The purpose of this invention is to provide an automated insulin injection device and control method for monitoring blood glucose and blood potassium, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an automatic insulin injection control method, comprising the following steps: S1: Real-time acquisition of glucose and potassium ion concentrations in the wearer's subcutaneous tissue fluid via a wearable flexible dual-mode sensor patch; S2: Based on the potassium ion concentration, body temperature data, and historical calibration data, the potassium ion concentration is converted into an estimated serum potassium concentration using a lightweight calibration model deployed on the local controller; S3: Determine whether the glucose concentration is higher than the first blood glucose threshold, and at the same time determine whether the estimated serum potassium concentration is within the preset safe potassium concentration range; S4: Only when the glucose concentration is higher than the first blood glucose threshold and the estimated serum potassium concentration is within the safe potassium concentration range, an insulin injection command is generated, and the micro-insulin pump is controlled to execute a subcutaneous injection of the corresponding dose of insulin. S5: If the estimated serum potassium concentration is higher than the first high potassium threshold, then any automatic insulin injection is prohibited and a high potassium alarm is triggered. If the estimated serum potassium concentration is lower than the first low potassium threshold, then the maximum single insulin injection dose is limited to a preset safety limit.

[0007] In this preferred embodiment, the safe potassium concentration range is 3.5 mmol / L to 5.0 mmol / L, the first high potassium threshold is 5.5 mmol / L, and the first low potassium threshold is 3.0 mmol / L. This range covers the normal physiological range of serum potassium in adults, and a warning buffer zone is set outside the boundary, enabling early identification and intervention for hyperkalemia and hypokalemia. Compared with existing technologies that trigger insulin injection only with a fixed blood glucose threshold, this design significantly improves the safety of high-risk groups such as those with diabetic nephropathy, heart failure, or those using potassium-sparing diuretics. It avoids the risk of sudden death caused by insulin-induced potassium influx masking the true hyperkalemia state, achieving the effect of clinical-grade electrolyte safety protection.

[0008] In this preferred embodiment, the lightweight calibration model is a neural network model trained based on an individual's historical fingertip blood potassium test values. The model inputs include: real-time tissue fluid potassium ion concentration, skin temperature, heart rate variability, and activity level data, and the output is the calibrated estimated serum potassium concentration. The model automatically updates the weight parameters weekly based on newly added calibration points.

[0009] In this preferred embodiment, before executing step S4, the following safety conditions are verified: sufficient insulin reservoir capacity, unobstructed infusion tubing, battery power exceeding the minimum operating threshold, and the user not manually disabling the auto-injection function. If any safety condition is not met, auto-injection is paused and a corresponding fault warning is issued. By employing a lightweight neural network model trained based on individual fingertip potassium calibration points and integrating dynamic physiological parameters such as skin temperature, heart rate variability, and activity level for serum potassium estimation, the physiological lag and individual differences between tissue fluid and serum potassium are effectively compensated. This solves the technical bottleneck of existing potassium ion sensors being unable to be used for clinical decision-making due to poor tissue fluid-serum correlation, thus ensuring the reliability of the safety gating logic. Simultaneously, multiple safety verifications are added before injection, including dosage, tubing patency, battery power, and user authorization status, forming a three-in-one safety protection system of "physiological parameters + device status + user intent." This avoids accidental injection due to mechanical failure or operational negligence, further enhancing the system's robustness and clinical reliability.

[0010] A blood glucose and potassium monitoring and automatic insulin injection device, comprising: A flexible dual-mode sensing patch integrates a glucose oxidase working electrode, a potassium ion selective electrode, a reference electrode, and a digital temperature sensor to collect glucose concentration, potassium ion concentration, and local temperature in subcutaneous tissue fluid. A miniature insulin pump, comprising a screw drive mechanism, a 1.5–3.0 mL insulin reservoir, and an outlet connection port; The controller is electrically connected to the flexible dual-mode sensor patch and the micro insulin pump and is configured to execute the automatic insulin injection control method described above. An arc-shaped waist-worn housing is used to integrate and fix the flexible dual-mode sensor patch, micro insulin pump and controller to the user's lumbar and abdominal area. A retractable flexible tube connects at one end to the outlet of the micro-insulin pump and at the other end to the subcutaneous indwelling needle holder in the abdomen. The tube is laid out along the guide groove on the inner side of the arc-shaped waist-worn housing. By integrating the flexible dual-mode sensor patch, the micro-insulin pump, and the controller into the arc-shaped waist-worn housing, and configuring the retractable flexible tube laid out along the guide groove on the inner side of the housing to connect to the indwelling needle holder in the abdomen, the entire monitoring-decision-dosing chain is physically integrated and ergonomically designed. The waist fat thickness is moderate, and the movement is relatively stable, making it suitable for long-term sensor wear. At the same time, the drug is delivered to the abdomen—the optimal area for insulin absorption—through the flexible tube, realizing a true "single-device closed-loop" function. Compared with the existing technology where the CGM patch (upper arm) and insulin pump (waist and abdomen) are worn separately and require multiple devices to work together, this design greatly simplifies user operation, reduces the number of devices, shortens system response latency, and improves wearing comfort and compliance, achieving a unified effect of high integration and clinical practicality.

[0011] In this preferred embodiment, the flexible dual-mode sensing patch is detachably mounted to the sensing window of the arc-shaped waist-worn housing via a magnetic strip, facilitating replacement. The magnetic interface incorporates electrical contacts for rapid connection of the sensing signal and power supply. Magnetic adsorption ensures precise patch positioning, while gold-plated contacts guarantee low contact resistance and signal integrity, achieving plug-and-play functionality and convenient long-term maintenance for the sensor module. Compared to existing CGM systems that require removing the old patch and attaching a new one, which can cause skin irritation or positioning errors, this design significantly reduces the complexity of replacement operations, minimizes the risk of skin damage, and ensures consistent electrode contact after each replacement, achieving the dual benefits of improved user experience and sensing reliability.

[0012] In a preferred embodiment of this solution, the controller is further configured to: when the estimated serum potassium concentration is detected to be higher than a first hyperkalemia threshold, drive the vibration motor and indicator light to issue a hyperkalemia alarm, and push an emergency notification to the paired mobile terminal via Bluetooth module. Hyperkalemia has an insidious onset but serious consequences; a single alert method is easily overlooked. Multimodal alarms ensure that the alarm is still detected in environments such as sleep and noisy conditions, achieving proactive early warning of life-threatening electrolyte imbalances. Compared to existing systems that only display abnormal values ​​in the app or record them silently, this design significantly improves the response speed to emergencies, providing users with a critical window for medical treatment and achieving an alarm effect at the level of life safety assurance.

[0013] In this preferred embodiment, the curved waist-worn housing houses a wireless charging coil and a waterproof sealed cavity. The controller, micro insulin pump, and lithium polymer battery are all encapsulated within the waterproof sealed cavity. A display screen is located on the outer surface of the curved waist-worn housing to display glucose concentration, estimated serum potassium concentration, and remaining insulin dose in real time. The sealed cavity prevents sweat and rainwater from entering and causing short circuits; wireless charging avoids frequent plugging and unplugging, leading to interface aging; and constantly displayed key parameters reduce the user's reliance on frequently checking their phone, achieving reliable operation and information transparency around the clock. Compared to existing insulin pump solutions that require wired charging, lack a local screen, or only display basic status, this design improves device durability and battery life convenience while enhancing the user's sense of control over their metabolic state, achieving a fusion of medical-grade reliability and consumer-grade experience.

[0014] In this preferred embodiment, the potassium ion selective electrode is a valine-modified polyvinyl chloride membrane electrode, whose working potential is in the range of +50 mV to +150 mV relative to the Ag / AgCl reference electrode, and is spatially isolated from the glucose oxidase working electrode to avoid electrochemical interference.

[0015] In this preferred embodiment, a detachable top cover is bolted to the top surface of the arc-shaped waist-wearing housing above the waterproof sealing cavity. A USB charging port is provided on the outer wall of the arc-shaped waist-wearing housing. The waist belt has two fixed connection ends, which are connected by Velcro. A power button is provided on the outer wall of the arc-shaped waist-wearing housing.

[0016] Compared with the prior art, the technical effects and advantages of the present invention are as follows: This automated insulin injection device, which monitors blood glucose and potassium levels, simultaneously acquires the glucose and potassium concentrations of subcutaneous tissue fluid in real time via a wearable flexible dual-mode sensor patch. Combining this with multi-source physiological information such as body temperature and historical calibration data, and utilizing a lightweight calibration model deployed on a local controller, the device dynamically converts the tissue fluid potassium concentration into a clinically interpretable estimated serum potassium concentration. This allows the system to overcome the limitations of traditional continuous glucose monitoring (CGM) which relies solely on a single blood glucose parameter, introducing electrolyte homeostasis as a key safety dimension in a closed-loop insulin control system for the first time. Furthermore, by setting a dual-judgment logic—allowing automatic injection only when blood glucose is above a first threshold and estimated serum potassium is within a safe range—an intelligent drug delivery mechanism with serum potassium levels as a hard safety gating is achieved. This mechanism effectively identifies high-risk states such as hyperkalemia or hypokalemia during operation: when the estimated serum potassium concentration exceeds 5.5 mmol / L (the first hyperkalemia threshold), the system actively prohibits any automated insulin injections and triggers multi-level alarms; when serum potassium is below 3.0 mmol / L (the first hypokalemia threshold), it limits the maximum single dose to prevent insulin from further exacerbating hypokalemia. Compared with existing artificial pancreas systems based solely on blood glucose feedback (such as Medtronic 780G or Tandem Control-IQ), this approach significantly reduces the risk of serious adverse events (such as fatal arrhythmias) caused by blindly lowering blood glucose in complex clinical scenarios such as renal insufficiency, heart failure, or drug interference, especially improving the treatment safety and applicability for patients with diabetes and chronic kidney disease.

[0017] By integrating a flexible dual-mode sensing patch, a micro-pump, and a controller into an ergonomically designed curved waist-worn shell, and employing a magnetic quick-change interface and a retractable flexible tube with guide slots, this system not only achieves integrated monitoring and drug delivery functions but also ensures that insulin is accurately infused to the optimal absorption site in the abdomen, balancing system response speed and user comfort. Furthermore, the spatial isolation layout of the valine-PVC membrane potassium electrode fundamentally suppresses cross-interference from glucose oxidation byproducts on potassium detection, guaranteeing the long-term stability of dual-parameter sensing. In summary, this technical solution, through a complete technology chain of "dual-parameter collaborative sensing—personalized correction—safety gating decision—multi-state verification—integrated structure realization," not only surpasses existing single-parameter closed-loop systems in functionality but also achieves significant progress in safety, applicability to a wider range of populations, and user experience, demonstrating outstanding clinical value and industrialization prospects. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the disassembled structure of the flexible dual-mode sensing patch of the present invention; Figure 3 This is a schematic diagram of the structure of the flexible dual-mode sensing patch of the present invention; Figure 4 This is a schematic diagram of the disassembly structure of the arc-shaped waist-worn housing of the present invention.

[0020] Explanation of reference numerals in the attached figures: In the diagram: 1. Waist belt; 2. Fixed connection end; 3. Velcro; 4. Arc-shaped waist-wearing shell; 5. Display screen; 6. Power button; 7. USB charging port; 8. Flexible dual-mode sensor patch; 9. Removable top cover; 10. Indicator light; 11. Glucose oxidase working electrode; 12. Potassium ion selective electrode; 13. Ag / AgCl reference electrode; 14. Digital temperature sensor; 15. Magnetic strip; 16. Controller; 17. Mini insulin pump; 18. Insulin storage compartment; 19. Outlet connection port; 20. Tube; 21. Lithium polymer battery; 22. Waterproof sealing cavity. Detailed Implementation

[0021] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0022] Unless otherwise defined, the directions mentioned herein, such as up, down, left, right, front, back, inside, and outside, are based on the directions shown in the figures of this invention, and are explained here together.

[0023] Example 1: As Figures 1-4 As shown, the present invention provides a blood glucose and potassium monitoring and automatic insulin injection device, which includes: Flexible dual-mode sensor patch 8; Mini insulin pump 17; Controller 16; 4. Arc-shaped waist-worn shell; Retractable hose assembly 20; A subcutaneous needle hub was placed in the abdomen.

[0024] The flexible dual-mode sensor patch 8 is attached to the skin surface of the user's waist and abdomen, and integrates the following internal components: The glucose oxidase working electrode 11 is used to catalyze the generation of an electric current signal from glucose in tissue fluid. The potassium ion selective electrode 12 uses a valine-modified polyvinyl chloride (PVC) membrane as the sensitive layer. Ag / AgCl reference electrode 13; Digital temperature sensor 14 is used to monitor local skin temperature in real time.

[0025] In this embodiment, the electrodes are fabricated on a flexible polyimide substrate using microfabrication technology, with a minimum spacing of 2 mm between each electrode to avoid electrochemical interference from hydrogen peroxide generated during glucose oxidation on the potassium ion electrode. The operating potential of the potassium ion selective electrode 12 is stable within the range of +50 mV to +150 mV relative to the Ag / AgCl reference electrode, ensuring a high selective response to K⁺.

[0026] In this embodiment, the miniature insulin pump 17 includes a precision screw drive mechanism, a 2.0 mL insulin reservoir 18, and an outlet connection port 19. This pump achieves a minimum injection step accuracy of 0.05 U and a maximum infusion rate of 5 U / h.

[0027] In this embodiment, the controller 16 employs a low-power ARM Cortex-M33 core microcontroller (such as STM32U585), which integrates a 16-bit analog-to-digital converter (ADC), a Bluetooth 5.3 communication module, a vibration motor drive circuit, and an OLED display drive interface. The controller 16 is electrically connected to the flexible dual-mode sensor patch 8 via a flexible ribbon cable and controls the micro insulin pump 17 through the motor drive circuit.

[0028] In this embodiment, the arc-shaped waist-worn housing 4 is made of medical-grade silicone and engineering plastic composite, and has an arc-shaped structure that conforms to the curvature of the human waist, allowing it to be comfortably fixed to the user's left or right waist. The inner side of the housing 4 is provided with a sensing window and a flexible tube guide groove. The flexible dual-mode sensing patch 8 is detachably installed at the sensing window via a magnetic strip 15. This magnetic strip 15 has built-in spring-loaded pin-type electrical contacts, which automatically establish a power supply and signal path when the patch is in place, facilitating weekly replacement of the sensing patch by the user.

[0029] In this embodiment, one end of the retractable tubing assembly 20 is connected to the outlet port 19 of the micro insulin pump 17, and the other end is connected to the indwelling needle hub pre-placed in the subcutaneous tissue of the abdomen. The tubing 20 is laid along the guide groove inside the housing 4 to avoid bending. The tubing assembly 20 includes a section of elastic corrugated tubing and a manually locking buckle. When the user needs to replace the insulin reservoir 18, the buckle can be released to temporarily disconnect the tubing without removing the indwelling needle hub in the abdomen, reducing the number of punctures and the risk of infection.

[0030] In this embodiment, the housing 4 has a waterproof sealed cavity 22 inside, which encapsulates the controller 16, the micro insulin pump 17, and the lithium polymer battery 21. A wireless charging coil is embedded in the top of the cavity, supporting Qi standard wireless charging. The outer surface of the housing has a display screen 5, which displays the current tissue fluid glucose concentration, estimated serum potassium concentration, remaining insulin dose, battery power, and system status in real time.

[0031] Example 2: The controller 16 periodically (e.g., every 2 minutes) performs the following steps to implement the automatic insulin injection control method of claim 1: Step S1: The original electrical signal is acquired through the flexible dual-mode sensor patch 8. After ADC conversion, the current glucose concentration in the subcutaneous tissue fluid is calculated to be 12.8 mmol / L, the potassium ion concentration is 4.6 mmol / L, and the local skin temperature is 33.2°C.

[0032] Step S2: Controller 16 invokes the locally deployed lightweight calibration model. This model is a three-layer fully connected neural network with an input dimension of 5, including: Real-time potassium ion concentration in tissue fluid (4.6 mmol / L); Skin temperature (33.2°C); Heart rate variability (HRV, transmitted from the paired smartwatch via BLE, value 42 ms); User activity level (derived from the integration of the built-in accelerometer, with a value of "light activity"); The time interval between the last finger-prick blood potassium calibration (3 days).

[0033] The model outputs an estimated serum potassium concentration, which, after inference, is 5.1 mmol / L. The model was trained using eight finger-prick potassium measurements taken by the user over the past four weeks, and the weight parameters are automatically updated weekly with new calibration points to ensure long-term accuracy.

[0034] Step S3: Controller judgment: Is the glucose concentration (12.8 mmol / L) higher than the first blood glucose threshold (set at 10.0 mmol / L)? Estimate whether the serum potassium concentration (5.1 mmol / L) is within the preset safe potassium concentration range [3.5, 5.0] mmol / L.

[0035] Step S4: Because blood potassium levels are slightly above the safe upper limit, no insulin injection instruction is generated, and the system enters observation mode. If glucose continues to rise and blood potassium levels return to the safe range, an injection can be triggered in subsequent cycles.

[0036] In another scenario: with a glucose concentration of 14.2 mmol / L and an estimated serum potassium concentration of 4.3 mmol / L (in the range of [3.5, 5.0]), the controller calculates the required insulin dose of 1.3 U based on a preset algorithm (such as modified PID control) and generates an injection command to drive the micro insulin pump 17 to complete the injection.

[0037] Step S5: If the estimated serum potassium concentration is 5.7 mmol / L (above the first hyperkalemia threshold of 5.5 mmol / L), the system will disable any automated insulin injections. Simultaneously: The vibration motor is driven to emit a vibration that lasts for 2 seconds; Turn on the red indicator light 10; An emergency notification for high potassium levels is pushed to the user's mobile app via Bluetooth: "High potassium risk detected, please seek medical attention immediately!"

[0038] If the estimated serum potassium concentration is 2.8 mmol / L (below the first low potassium threshold of 3.0 mmol / L), even if the blood glucose is as high as 18 mmol / L, the system will limit the maximum single insulin injection dose to 0.5 U (preset safety upper limit) to prevent insulin from further lowering serum potassium and causing arrhythmia.

[0039] In addition, before performing step S4, controller 16 also verifies the following safety conditions: Is the insulin storage tank capacity ≥ 10 U? The pressure sensor reading in the infusion line is normal (is there any blockage?). Is the battery level ≥ 15%? Is the user not using the "Pause Auto-Injection" switch in the app?

[0040] If any condition is not met (such as insufficient dosage), the automatic injection will be paused, and the message "Insufficient dosage, please replace the cartridge" will be displayed on screen 5, along with a vibration prompt.

[0041] Example 3: In this example, the sensitive membrane of the potassium ion selective electrode 12 is formed by spin coating of valinemycin (2% w / w), PVC (33%), and dioctyl phthalate (DOP, 65%) dissolved in tetrahydrofuran, with a thickness of about 100 μm. In this embodiment, the magnetic strip 15 adopts a combination of neodymium iron boron magnetic ring and gold-plated copper contacts, with an insertion and removal life of ≥500 times; In this embodiment, the retractable hose 20 is made of medical-grade polyurethane, with an inner diameter of 0.3 mm and an outer diameter of 0.8 mm. The corrugated section can be stretched to 1.5 times its original length. In this embodiment, the display screen 5 supports a low-power always-on display mode, which only displays key values, and the standby power consumption is <0.5 mA.

[0042] It should be noted that, in this document, relational terms such as "one" and "two" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An insulin automatic injection control method characterized by, Includes the following steps: S1: The glucose concentration and potassium ion concentration in the subcutaneous tissue fluid of the wearer can be obtained in real time through a wearable flexible dual-mode sensor patch (8); S2: Based on the potassium ion concentration, body temperature data and historical calibration data, the potassium ion concentration is converted into an estimated serum potassium concentration using a lightweight calibration model deployed on the local controller (16); S3: Determine whether the glucose concentration is higher than the first blood glucose threshold, and at the same time determine whether the estimated serum potassium concentration is within the preset safe potassium concentration range; S4: Only when the glucose concentration is higher than the first blood glucose threshold and the estimated serum potassium concentration is within the safe potassium concentration range, an insulin injection command is generated and the micro-insulin pump (17) is controlled to perform a subcutaneous injection of the corresponding dose of insulin; S5: If the estimated serum potassium concentration is higher than the first high potassium threshold, then any automatic insulin injection is prohibited and a high potassium alarm is triggered. If the estimated serum potassium concentration is lower than the first low potassium threshold, then the maximum single insulin injection dose is limited to a preset safety limit.

2. The method of claim 1, wherein: The safe potassium concentration range is 3.5 mmol / L to 5.0 mmol / L, the first high potassium threshold is 5.5 mmol / L, and the first low potassium threshold is 3.0 mmol / L.

3. The method for controlling automatic insulin injection according to claim 1, characterized in that: The lightweight calibration model is a neural network model trained based on an individual's historical fingertip blood potassium test values. The model inputs include: real-time tissue fluid potassium ion concentration, skin temperature, heart rate variability and activity level data, and the output is the calibrated estimated serum potassium concentration. The model automatically updates the weight parameters weekly based on new calibration points.

4. The method for controlling automatic insulin injection according to claim 1, characterized in that: Before performing step S4, the following safety conditions are verified: the insulin reservoir (18) has sufficient reserves, the infusion line is unblocked, the battery power is above the minimum operating threshold, and the user has not manually disabled the auto-injection function. If any safety condition is not met, the auto-injection is suspended and a corresponding fault message is issued.

5. A blood glucose and potassium monitoring and automatic insulin injection device, characterized in that, include: A flexible dual-mode sensing patch (8) integrates a glucose oxidase working electrode (11), a potassium ion selective electrode (12), a reference electrode (13) and a digital temperature sensor (14) to collect glucose concentration, potassium ion concentration and local temperature in subcutaneous tissue fluid. A miniature insulin pump (17) includes a screw drive mechanism, an insulin reservoir (18) with a capacity of 1.5–3.0 mL, and an outlet connection port (19). The controller (16), electrically connected to the flexible dual-mode sensing patch (8) and the micro insulin pump (17), is configured to perform the insulin auto-injection control method as described in any one of claims 1-4; The curved waist-worn housing (4) is used to integrate and fix the flexible dual-mode sensing patch (8), the micro insulin pump (17) and the controller (16) to the user's waist and side abdomen area; A retractable tubing (20) is connected at one end to the outlet of the micro insulin pump (17) and at the other end to the subcutaneous indwelling needle seat in the abdomen. The tubing (20) is laid along the guide groove on the inner side of the arc-shaped waist-worn housing (4).

6. The blood glucose and potassium monitoring and automatic insulin injection device according to claim 5, characterized in that: The flexible dual-mode sensor patch (8) is detachably installed at the sensing window of the arc-shaped waist-worn housing (4) via a magnetic strip (15) for easy replacement. The magnetic interface has built-in electrical contacts for quick connection of sensing signals and power supply.

7. The blood glucose and potassium monitoring and automatic insulin injection device according to claim 5, characterized in that: The controller (16) is also configured to: when the estimated serum potassium concentration is detected to be higher than the first high potassium threshold, drive the vibration motor and indicator light (10) to issue a high potassium alarm, and push an emergency notification to the paired mobile terminal via the Bluetooth module.

8. The blood glucose and potassium monitoring and automatic insulin injection device according to claim 5, characterized in that: The arc-shaped waist-wearing housing (4) is equipped with a wireless charging coil and a waterproof sealing cavity (22). The controller (16), the micro insulin pump (17) and the lithium polymer battery (21) are all encapsulated in the waterproof sealing cavity (22). The outer surface of the arc-shaped waist-wearing housing (4) is equipped with a display screen (5) for real-time display of glucose concentration, estimated serum potassium concentration and remaining insulin dose.

9. The blood glucose and potassium monitoring and automatic insulin injection device according to claim 5, characterized in that: The potassium ion selective electrode (12) is a valine-modified polyvinyl chloride membrane electrode with a working potential in the range of +50 mV to +150 mV relative to the Ag / AgCl reference electrode (13), and is spatially isolated from the glucose oxidase working electrode (11) to avoid electrochemical interference.

10. A blood glucose and potassium monitoring and automatic insulin injection device according to claim 8, characterized in that: A removable top cover (9) is bolted to the top surface of the arc-shaped waist-wearing housing (4) above the waterproof sealing cavity (22). A USB charging port (7) is provided on the outer wall of the arc-shaped waist-wearing housing (4).

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