Intelligent electric needleless injector and control method

Abstract

The invention discloses an intelligent electric needleless injector and a control method, and relates to the technical field of medical instruments. The medicine tube assembly comprises a medicine tube and a piston which is arranged in the medicine tube in a sliding manner; the push rod is connected with the piston; the electromagnetic driving assembly is arranged in the shell and comprises a mover fixedly connected with the push rod and a stator surrounding the mover and arranged in the movement direction of the mover, the stator comprises a plurality of independently controllable electromagnetic coils, and the position detection assembly is used for detecting the absolute position of the push rod or the mover in real time and generating a position signal; the control assembly comprises a micro-control unit and a driving circuit, and the control assembly is configured to independently control the power-on states of the electromagnetic coils through the driving circuit according to the target dosage and the position signals so as to drive the rotor to execute medicine suction or injection operation; accurate adjustment of injection dosage and speed is achieved, and stability of the injection process and safety of equipment operation are improved.

Description

Technical Field

[0001] This invention relates to the field of needle-free injector technology in the medical device industry, and more particularly to an intelligent electric needle-free injector and its control method. Background Technology

[0002] Needle-free injection is a drug delivery method that uses a high-pressure jet to penetrate the skin and deliver medication to the intradermal, subcutaneous, or muscle tissue without the need for needles. Compared to traditional needle injection, needle-free injection offers significant advantages such as eliminating needle phobia, avoiding needlestick injuries, reducing the risk of cross-infection, improving drug absorption rates, and enhancing patient compliance. It shows broad application prospects in fields such as insulin, growth hormone, vaccines, and mass immunization.

[0003] There are three main types of needle-free injectors: spring-powered, pneumatic, and electric.

[0004] Spring-loaded needle-free injectors store mechanical energy by manually compressing a spring, which is then released instantaneously upon triggering to push the piston and initiate injection. This type of structure relies entirely on mechanical transmission and has the following inherent drawbacks: First, the spring's elasticity means its output force decreases with increasing stroke, making it difficult to maintain stable pressure throughout the injection process. This results in insufficient injection kinetic energy or excessive residual energy, affecting drug delivery depth and distribution uniformity. Second, the spring's compression stroke lacks a precise quantitative correlation with the injection dose, requiring the operator to manually set the aspirate volume based on experience. This leads to low dose control accuracy, making it unsuitable for small-dose or high-precision drug delivery scenarios. Third, manual charging is required before each injection, which is cumbersome and results in inconsistent operation depending on the individual. Fourth, after prolonged use, the spring is prone to fatigue deformation, gradually reducing output force and causing unstable device performance.

[0005] Pneumatic needle-free injectors use high-pressure gas (such as carbon dioxide cylinders or compressed air) as a power source, and the gas release is controlled by a gas valve to push the piston. Although these injectors can achieve high injection speeds and relatively stable output, their structure is complex, usually requiring a gas cylinder or external gas source, and the device is large and heavy, making it poorly portable; the gas pressure is significantly affected by ambient temperature, and the gas pressure drops in low-temperature environments, making it difficult to guarantee consistent injection depth; in addition, gas cylinders are pressure vessels, which restrict transportation and storage, resulting in high operating costs.

[0006] With the development of electromagnetic technology, several electric needle-free injector solutions have emerged in recent years. Existing electric needle-free injectors typically employ an electromagnetic drive structure, using an electric current to generate electromagnetic force that drives the plunger for injection. However, these solutions still have the following technical limitations in practical applications:

[0007] First, the controllability of the driving force is insufficient. In existing electromagnetic drive structures, the output force characteristics are difficult to maintain stability and controllability throughout the entire stroke of the push rod. Especially at different stages of the stroke, the driving force often exhibits non-uniform changes, resulting in insufficient push force at the beginning of injection or energy overshoot at the end of injection, affecting the stability and consistency of drug delivery.

[0008] Second, the dynamic adjustment capability of the injection process is lacking. Most existing solutions can only achieve simple start and stop control, making it difficult to finely adjust the speed and displacement of the plunger. The speed curve during the injection process cannot be differentiated according to drug characteristics (such as viscosity and dosage) or injection site requirements (intradermal, subcutaneous, or intramuscular), making it difficult to meet the needs of personalized drug delivery.

[0009] Third, the accuracy of dosage control is limited by the open-loop method. Existing solutions lack a real-time sensing and dynamic adjustment mechanism for the actuator's movement. Dosage control usually relies on the open-loop method. When the drug tube is replaced, the piston resistance changes, or the drug viscosity fluctuates, deviations can easily occur between the actual injection volume and the set dose, making it difficult to guarantee dosage repeatability and accuracy in long-term use. Summary of the Invention

[0010] Based on the above problems, the purpose of this invention is to provide an intelligent electric needleless injector and control method. By using an independently controllable electromagnetic coil array to drive the mover, and combining real-time position detection and closed-loop control, the precise programmable adjustment of injection dosage and speed, as well as flexible braking at the end of the injection stroke, are realized, thereby improving the stability of the injection process and the safety of equipment operation.

[0011] In a first aspect, the present invention provides an intelligent electric needle-free injector, comprising:

[0012] case;

[0013] A medicine tube assembly includes a medicine tube for containing a liquid medicine and a piston slidably disposed within the medicine tube;

[0014] The push rod connected to the piston;

[0015] An electromagnetic drive assembly is disposed within the housing and includes a mover fixedly connected to the push rod and a stator surrounding the mover and arranged along its direction of motion. The stator includes multiple independently controllable electromagnetic coils for generating electromagnetic force when energized to drive the mover to perform linear motion.

[0016] A position detection component is used to detect the absolute position of the push rod or the moving part in real time and generate a position signal;

[0017] A control component, comprising a microcontroller unit and a drive circuit, is configured to independently control the energizing state of the plurality of electromagnetic coils via the drive circuit based on the target dose and the position signal, so as to drive the mover to perform a drug aspiration or injection operation.

[0018] Preferably, the stator includes at least three independently controllable electromagnetic coils arranged equidistantly along the axial direction, the electromagnetic coils being isolated from each other by insulating spacers, and each electromagnetic coil being independently controlled by the drive circuit to control its energization state.

[0019] Preferably, the mover has a stepped cylindrical structure, including a guide portion with a first diameter at the front end, a magnetic coupling portion with a second diameter in the middle, and a connecting portion with a third diameter at the rear end. There is an air gap of 0.1-0.5mm between the outer diameter of the magnetic coupling portion and the inner diameter of the electromagnetic coil. The mover and the push rod are integrally formed or fixedly connected, wherein the second diameter > the third diameter > the first diameter.

[0020] Optionally, the position detection assembly includes a magnetostrictive displacement sensor with a waveguide wire extending along the axial direction of the push rod and a position magnet disposed on the mover.

[0021] Optionally, the position detection component includes an array of linear Hall sensors arranged along the axial direction and a permanent magnet disposed on the mover. The microcontroller calculates the absolute position of the push rod by detecting the position of the permanent magnet through the Hall sensor array.

[0022] Preferably, the control component is further configured to:

[0023] A preset injection speed curve is obtained during the injection operation, and the injection speed curve includes at least an acceleration phase, a constant speed injection phase, and a deceleration buffer phase.

[0024] The travel range of the moving part is determined based on the position signal;

[0025] During the acceleration phase, the plurality of electromagnetic coils are sequentially energized along the direction of motion of the mover to generate a traveling wave magnetic field to accelerate the mover.

[0026] When in the constant speed injection stage, the current speed is calculated in real time based on the position signal, and the closed-loop control algorithm is used to dynamically adjust the current of the electromagnetic coil that is currently aligned with the mover in the direction of motion in order to maintain a constant speed.

[0027] When in the deceleration and buffering phase, the electromagnetic coil located in front of the mover along the direction of the mover's movement is energized to generate a reverse braking force, causing the mover and push rod to decelerate before the end of their stroke.

[0028] Preferably, the control component is further configured to:

[0029] During the injection operation, the electromagnetic coil number corresponding to the magnetic coupling part of the mover is determined based on the position signal;

[0030] When driving the mover to perform the injection action, the electromagnetic coil currently corresponding to the magnetic coupling part and at least one electromagnetic coil adjacent to it along the direction of motion are simultaneously energized to form a magnetic field superposition area.

[0031] Based on the preset injection speed curve and the position signal, the magnitude of the thrust on the magnetic coupling part is adjusted in real time by adjusting the total magnetic flux of the magnetic field superposition area, so that the deviation between the actual movement speed of the push rod and the preset injection speed curve is kept within a preset range.

[0032] Furthermore, the control component is also configured to:

[0033] During the acceleration phase of the injection operation, multiple electromagnetic coils are sequentially controlled to form magnetic field superposition regions along the direction of motion, with the number of electromagnetic coils in each superposition region gradually increasing to achieve a gradient increase in thrust; or

[0034] During the deceleration and buffering phase of the injection operation, multiple electromagnetic coils are sequentially controlled to form magnetic field superposition zones along the direction of motion, and the number of electromagnetic coils contained in each magnetic field superposition zone gradually decreases to achieve a gradient reduction in thrust.

[0035] Secondly, the present invention proposes a control method for the intelligent electric needle-free injector described in the embodiments of the present invention, comprising the following steps:

[0036] The control component receives the target dose command; and calculates the target displacement of the push rod based on the target dose.

[0037] In drug inhalation mode, the control component controls the plurality of electromagnetic coils through the drive circuit to generate electromagnetic force in a first direction, driving the mover and push rod to move backward.

[0038] In injection mode, the control component controls the plurality of electromagnetic coils through the drive circuit to generate an electromagnetic force in a second direction opposite to the first direction, driving the mover and push rod to move forward;

[0039] The control component continuously receives the position signal from the position detection component and adjusts the control of the electromagnetic coil in real time according to the position signal, forming a closed-loop control of the push rod displacement and / or speed.

[0040] Preferably, the step of adjusting the control of the electromagnetic coil in real time according to the position signal includes:

[0041] Obtain a preset injection speed curve, which includes at least an acceleration phase, a constant speed injection phase, and a deceleration buffer phase.

[0042] The travel range of the moving part is determined based on the position signal;

[0043] During the acceleration phase, the plurality of electromagnetic coils are sequentially energized along the direction of motion of the mover to generate a traveling wave magnetic field to accelerate the mover.

[0044] When in the constant speed injection stage, the current speed is calculated in real time based on the position signal, and the closed-loop control algorithm is used to dynamically adjust the current of the electromagnetic coil that is currently aligned with the mover in the direction of motion in order to maintain a constant speed.

[0045] When in the deceleration and buffering phase, the electromagnetic coil located in front of the mover along the direction of the mover's movement is energized to generate a reverse braking force, causing the mover and push rod to decelerate before the end of their stroke.

[0046] Compared with existing technologies, the beneficial effects of this invention include at least the following: by employing a stator composed of multiple independently controllable electromagnetic coils, combined with a position detection component that detects the absolute position of the push rod or mover in real time, the control component can precisely control the stroke and speed of the mover according to the target dose and preset parameters. This overcomes the limitations of traditional needle-free injectors that rely on mechanical limits or spring deformation to control the dose, achieving precise digital adjustment of the dose and supporting complex injection speed curves (such as acceleration, constant speed, and deceleration segmented control). Therefore, the kinetic energy of the drug solution during injection can be optimized according to different drug solution characteristics (such as viscosity and dosage) or patient needs, significantly reducing the impact pain at the moment of injection while ensuring the transdermal injection effect.

[0047] The electromagnetic drive assembly uses segmented, independently controllable electromagnetic coils, combined with a stepped mover structure (especially the air gap design between the magnetic coupling part and the coil). This allows the control assembly to dynamically select the combination of energized coils (such as energizing a single coil or stacking multiple coils to form a magnetic field superposition area) based on the current position of the mover. This not only achieves precise vector control of electromagnetic thrust, but also enables incremental thrust gradient during acceleration and flexible braking during deceleration. It effectively avoids the defects of large starting impact and violent end impact in traditional spring or single electromagnet drive methods, improving the stability of the injection process and the service life of the equipment.

[0048] Based on real-time position signals, the control component can accurately determine the stroke range of the actuator and dynamically adjust the drive current or the combination of energized coils to form a closed-loop control. This ensures that the deviation between the actual movement speed of the push rod and the preset injection speed curve is always kept within the preset range, thereby guaranteeing a high degree of consistency between injection depth and dosage and improving the reliability of treatment effect.

[0049] The mover and push rod are designed as a single piece or fixed connection, and with the electromagnetic coils arranged equidistantly along the axial direction, the backlash, friction, or energy loss present in traditional mechanical transmission structures (such as gears, lead screws, or spring energy storage mechanisms) is eliminated. The electromagnetic force acts directly on the mover fixed to the push rod, realizing a highly efficient conversion between electricity, magnetism, and force. This not only improves energy utilization but also simplifies the mechanical structure, facilitating the miniaturization and lightweight design of the equipment. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the overall structure of the intelligent electric needleless injector according to an embodiment of the present invention;

[0051] Figure 2 This is a cross-sectional schematic diagram of the electromagnetic drive component of the intelligent electric needleless injector according to an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of the intelligent electric needleless injector control method according to an embodiment of the present invention.

[0053] In the figure, 1 is the housing; 21 is the medicine tube; 22 is the piston; 3 is the push rod; 4 is the electromagnetic drive assembly; 41 is the electromagnetic coil; 421 is the guide part; 422 is the magnetic coupling part; 423 is the connecting part; and 5 is the insulating spacer. Detailed Implementation

[0054] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0055] The terms used to express position and direction in this invention are illustrated with reference to the accompanying drawings, but changes may be made as needed, and all such changes are included within the scope of protection of this invention.

[0056] Example 1:

[0057] See attached document Figure 1 and attached Figure 2This embodiment of an intelligent electric needleless injector includes: a housing 1, a drug tube assembly, a push rod 3, an electromagnetic drive assembly 4, a position detection assembly, and a control assembly.

[0058] The housing 1 is the main support structure of the syringe.

[0059] The medicine tube assembly includes a medicine tube 21 for containing liquid medicine and a piston 22 slidably disposed within the medicine tube 21. A push rod 3 is connected to the piston 22 for transmitting driving force.

[0060] The electromagnetic drive assembly 4 is housed inside the housing 1 and includes a mover and a stator. The mover is fixedly connected to the push rod 3 or integrally formed. The stator surrounds the mover and is arranged along its direction of motion. It includes multiple independently controllable electromagnetic coils 41, which are used to generate electromagnetic force when energized to drive the mover to move linearly.

[0061] The position detection component (not shown in the figure) is used to detect the absolute position of push rod 3 or mover in real time and generate a position signal.

[0062] The control components (not shown in the figure) include a microcontroller unit (MCU) and a drive circuit, configured to independently control the energizing state of multiple electromagnetic coils 41 based on the target dose and position signals, thereby driving the actuator to perform drug aspiration or injection operations. The MCU can be an industrial-grade microcontroller, such as the STM32 series.

[0063] In one possible implementation, the stator includes at least three independently controllable electromagnetic coils 41 arranged equidistantly along the axial direction, the electromagnetic coils 41 being isolated from each other by insulating spacers 5, and each electromagnetic coil 41 being independently controlled by the drive circuit to control its energization state.

[0064] For example, the electromagnetic coil 41 is wound with enameled copper wire, such as polyimide enameled wire, with a temperature resistance rating of 155℃, which can avoid insulation aging caused by long-term energization and heating. It has 600 turns, a wire diameter of 0.15mm, a rated current of 0.8A, a rated voltage of 12V, an axial length of 8mm, and an inner diameter of 12mm. It adopts a centralized winding method, which can maximize the magnetic flux density of the coil while reducing the space occupied by the coil, thus meeting the miniaturization requirements of needle-free injectors.

[0065] The mover has a stepped cylindrical structure, including a guide part 421 with a first diameter (outer diameter) at the front end, a magnetic coupling part 422 with a second diameter (outer diameter) in the middle, and a connecting part 423 with a third diameter (outer diameter) at the rear end, wherein the second diameter > the third diameter > the first diameter; the mover and the push rod 3 are integrally formed or fixedly connected.

[0066] An air gap of 0.1-0.5mm is left between the outer diameter of the magnetic coupling part 422 and the inner diameter of the electromagnetic coil 41, and its axial length matches the axial length of a single electromagnetic coil 41.

[0067] For example, the magnetic coupling part 422 uses a neodymium iron boron permanent magnet, which has the characteristics of excellent magnetic properties, small size, and light weight. It can generate sufficient electromagnetic coupling force in a limited space to meet the power requirements of needle-free injection. The surface of the magnetic coupling part 422 is galvanized with a thickness of 0.05mm, which can effectively prevent oxidation of the permanent magnet and improve its service life.

[0068] In a preferred implementation, the third diameter is 1.2-1.5 times the first diameter of the guide portion 421 and 60%-80% of the second diameter of the magnetic coupling portion 422. This size ratio balances connection strength and miniaturization, ensuring a reliable connection with the push rod (sufficient contact area) while avoiding insufficient space for stator coil layout due to an excessively large diameter of the connecting portion 423.

[0069] In one possible implementation, the position detection component includes a magnetostrictive displacement sensor. Its waveguide wire extends axially along the push rod 3 and is fixed to the inner wall of the housing 1; its position magnet is located at the end of the connecting portion 423 of the mover, parallel to the waveguide wire. When the control component sends a detection pulse, the pulse propagates along the waveguide wire, generating a strain pulse at the location of the position magnet. By measuring the time difference between pulse emission and echo reception, the absolute position of the mover is accurately calculated. This solution features non-contact operation, high precision, and strong anti-interference capability. For example, an MTS R-Series sensor can be selected, with a detection accuracy of 0.01 mm and a measurement range of 0-50 mm.

[0070] In another possible implementation, the position detection component includes an array of linear Hall sensors arranged along the axial direction and a permanent magnet mounted on the mover. As the mover moves, the magnetic field strength sensed by the Hall sensors at different positions changes. The control component reads the output values ​​of each Hall sensor and, combined with a magnetic field distribution model, calculates the absolute position of the permanent magnet. This solution is compact, relatively low-cost, and suitable for space-constrained integrated designs.

[0071] The working principle and effects of the above technical solution are as follows:

[0072] The electromagnetic drive assembly 4 adopts a cooperative structure of a mover (with a built-in permanent magnet) and a stator (multiple independent controllable electromagnetic coils 41). By controlling the energizing sequence of the coils, a traveling wave magnetic field that moves along the direction of motion can be formed, driving the mover to continuous linear motion.

[0073] This embodiment achieves the technical effect through the following structural design:

[0074] By arranging multiple independently controllable electromagnetic coils 41 along the direction of motion, and dynamically selecting the corresponding coil to be energized according to the position of the mover during the driving process, the long-stroke driving task is decomposed into a relay drive of multiple short-stroke coils. Each coil only undertakes the driving task within its effective working area, avoiding the nonlinear attenuation problem of electromagnetic force caused by stroke changes in traditional single electromagnetic coils, and effectively solving the technical problems of insufficient thrust in the initial stage and overshoot of thrust in the final stage.

[0075] The stepped mover structure achieves functional zoning by optimizing the diameter ratio of each part: the guide part 421 (minimum diameter) is used to reduce friction and radial positioning; the magnetic coupling part 422 (maximum diameter) is used for electromagnetic coupling, and its axial length matches that of a single coil, ensuring that the mover can form effective coupling with at least one coil at any position; the connecting part 423 (medium diameter) is used to fix it to the push rod, providing sufficient connection strength.

[0076] An optimized air gap of 0.1-0.5mm between the magnetic coupling unit 422 and the inner diameter of the electromagnetic coil 41 maximizes magnetic coupling efficiency while ensuring smooth movement. The lower limit of this air gap range (0.1mm) ensures no mechanical contact and minimizes magnetic resistance; the upper limit (0.5mm) takes into account manufacturing tolerances and thermal expansion to avoid interference. Compared to the 0.5-2mm air gap typically used in industrial linear motors, this solution achieves more efficient magnetic coupling.

[0077] With a diameter gradient design of second diameter > third diameter > first diameter, the magnetic coupling part 422 fully utilizes the radial space limited by the inner diameter of the coil to maximize magnetic flux; the connecting part 423 has a moderate diameter, ensuring connection strength while avoiding encroachment on the coil layout space; and the guide part 421 has the smallest diameter, reducing the contact area and lowering sliding friction. This design maximizes the compression of radial dimensions while ensuring electromagnetic performance, allowing the entire electromagnetic drive assembly 4 to be compactly integrated inside the housing 1.

[0078] The air gap between the magnetic coupling part 422 and the inner diameter of the electromagnetic coil 41, combined with the precise guidance of the guide part 421, ensures that the mover remains in a non-contact state with the electromagnetic coil 41 throughout its entire stroke. This avoids damage to the coil insulation layer caused by mechanical friction and significantly improves the service life of the electromagnetic drive assembly 4. Simultaneously, the non-contact motion prevents the accumulation of heat generated by friction, improving the thermal stability of the system.

[0079] The electromagnetic drive assembly 4 provides power output for both drug aspiration and injection, eliminating the need for a separate manual drug aspiration mechanism or auxiliary drive device. The control assembly can switch the direction of the driving force by changing the direction of the energized current in the electromagnetic coil 41, achieving one-button automated operation for drug aspiration and injection.

[0080] The position detection component acquires the absolute position signal of the mover or push rod 3 in real time and feeds it back to the control component. The control component calculates the required stroke based on the target dose and dynamically adjusts the energization state of each electromagnetic coil 41 through the drive circuit: in drug suction mode, a backward electromagnetic force is generated to drive the push rod 3 to move the piston 22 backward to draw in the drug; in injection mode, a forward electromagnetic force is generated to drive the push rod 3 to move the piston 22 forward to complete the injection. Throughout the process, the control component calculates the position, speed, and remaining stroke of the mover in real time based on the position signal, forming a closed-loop control circuit to ensure that the actual motion trajectory is consistent with the set trajectory.

[0081] Both magnetostrictive displacement sensors and linear Hall sensor arrays can be embedded, without significantly increasing the size of the device, meeting the portability requirements of needle-free injectors. They can be flexibly selected based on cost, accuracy, space and other needs.

[0082] In one possible implementation, the control component is further configured as follows:

[0083] A preset injection speed curve is obtained during the injection operation, and the injection speed curve includes at least an acceleration phase, a constant speed injection phase, and a deceleration buffer phase.

[0084] The travel range of the moving part is determined based on the position signal;

[0085] During the acceleration phase, the plurality of electromagnetic coils 41 are sequentially energized along the direction of motion of the mover to generate a traveling wave magnetic field to accelerate the mover.

[0086] When in the constant speed injection stage, the current speed is calculated in real time based on the position signal, and the closed-loop control algorithm is used to dynamically adjust the current of the electromagnetic coil 41 that is currently aligned with the mover in the direction of motion in order to maintain a constant speed.

[0087] When in the deceleration and buffering phase, the electromagnetic coil 41 located in front of the mover along the direction of the mover's movement is energized to generate a reverse braking force, causing the mover and push rod 3 to decelerate before the end of the stroke.

[0088] The injection speed curve is determined based on the drug administration parameters and pre-stored in the microcontroller unit. The drug administration parameters include at least one or more of the following: drug viscosity, target dose, and injection site type. The injection speed curve includes at least an acceleration phase, a constant-speed injection phase, and a deceleration buffer phase.

[0089] The real-time calculation of the current speed includes: the microcontroller calculates the current instantaneous speed based on the position signal difference between two adjacent sampling times and the sampling time interval; the dynamic adjustment of the energizing current includes: comparing the current instantaneous speed with the target speed at the corresponding time in the injection speed curve, and adjusting the driving current of the electromagnetic coil 41 based on the speed deviation using a proportional-integral-derivative control algorithm, so that the speed deviation converges to a preset threshold range;

[0090] The generation of reverse braking force includes: the microcontroller determines the distance between the current position of the mover and the end of the journey based on the position signal; when the distance is less than a preset deceleration start threshold, it controls at least one electromagnetic coil 41 located in front of the direction of movement of the mover to pass a current opposite to the direction of the driving current, thereby generating an electromagnetic force opposite to the direction of movement of the mover, causing the mover to decelerate and reduce its speed to below a preset safe speed at the end of the journey.

[0091] In one possible implementation, the control component is further configured as follows:

[0092] During the deceleration buffer phase, the distance between the current position of the mover and the end point of the stroke is determined based on the position signal. When the distance is less than the preset deceleration start threshold, reverse braking control is executed.

[0093] The reverse braking control includes:

[0094] The microcontroller determines the number N of electromagnetic coils 41 that need to be energized in front of the moving part based on the current speed and remaining travel of the moving part. N is an integer greater than or equal to 1, and N is positively correlated with the current speed and negatively correlated with the remaining travel.

[0095] The microcontroller calculates the required braking electromagnetic force according to the preset braking deceleration curve, and determines the input current value of each electromagnetic coil 41 participating in braking based on the mapping relationship between the braking electromagnetic force and the current of each electromagnetic coil 41. The direction of the input current is opposite to the direction of the driving current.

[0096] According to the determined number of coils and current value, the N electromagnetic coils 41 in front of the moving part are simultaneously supplied with the reverse current, generating a superimposed electromagnetic force opposite to the moving part's direction of motion, causing the moving part to decelerate and its speed to drop below the preset safe speed at the end of its journey.

[0097] In one possible implementation, the mapping relationship is as follows:

[0098] The braking electromagnetic force is proportional to the number of electromagnetic coils 41 involved in braking, and also proportional to the magnitude of the current flowing through each coil.

[0099] The microcontroller determines the input current value of each participating braking electromagnetic coil 41 according to the braking electromagnetic force using an equal current distribution method or a gradient current distribution method.

[0100] The equal current distribution method means that each electromagnetic coil 41 participating in braking is supplied with the same reverse current; the gradient current distribution method means that along the direction of motion of the mover, the electromagnetic coil 41 that is closer to the mover receives a larger reverse current.

[0101] In specific applications, the control component is configured to execute the following injection control logic:

[0102] The microcontroller unit (MCU) of the control component has multiple preset injection speed curves, each corresponding to a different combination of drug administration parameters. These parameters include drug viscosity (high, medium, low), target dose (0.1 mL, 0.5 mL, 1.0 mL, etc.), and injection site type (intradermal, subcutaneous, intramuscular). The operator can select these parameters via the syringe's human-machine interface (such as a touchscreen or buttons). The MCU automatically matches the corresponding injection speed curve based on the preset mapping relationship and loads it into its running memory. The injection speed curve is stored as a discrete point sequence, with each discrete point corresponding to a time point and its target speed value. The curve is divided into three continuous phases: an acceleration phase (0~...). ), constant rate injection phase ( ) and deceleration buffer phase ( ).

[0103] For example, for a subcutaneous insulin injection scenario (low drug viscosity, dose 0.3 mL, injection site subcutaneous), the matching injection speed curve parameters are: acceleration phase duration 30 ms, target speed linearly accelerates from 0 to 200 mm / s; constant speed injection phase duration 150 ms, target speed remains constant at 200 mm / s; deceleration buffer phase duration 20 ms, target speed linearly decelerates from 200 mm / s to 0.

[0104] When the MCU determines that the mover is in the travel range corresponding to the acceleration phase based on the position signal, it executes the traveling wave magnetic field driving strategy. Specifically, the MCU sequentially controls the electromagnetic coils 41 to be energized according to the direction of the mover's movement. Assuming the initial position of the mover corresponds to coil #1, the MCU first controls coil #1 to be energized, generating a positive electromagnetic force to propel the mover forward. When the mover moves to the transition region between coil #1 and coil #2, the MCU controls coil #1 to remain energized while simultaneously energizing coil #2, forming a magnetic field superposition. When the mover completely enters the effective range of coil #2, the MCU cuts off the energization of coil #1, leaving only coil #2 energized. This sequential switching forms a traveling wave magnetic field moving along the direction of motion.

[0105] During the acceleration phase, the energizing timing of adjacent electromagnetic coils 41 overlaps (i.e., the next coil is energized before the previous coil is completely de-energized). The overlap time is dynamically adjusted according to the current speed of the mover to ensure that the mover is continuously thrust during the switching process and to avoid thrust interruption or fluctuation.

[0106] When the MCU determines that the mover has entered the stroke range corresponding to the constant speed injection stage based on the position signal, it executes the speed closed-loop control strategy. The MCU reads the absolute position signal fed back by the position detection component at a fixed sampling period (e.g., 1ms), subtracts the position value at the current sampling moment from the position value at the previous sampling moment, and then divides by the sampling time interval to calculate the current instantaneous speed.

[0107] The MCU compares the current instantaneous speed with the target speed at the corresponding moment in the injection speed curve and calculates the speed deviation. A position-based PID control algorithm is used to calculate the required adjustment amount of the driving current for the electromagnetic coil 41. Based on the calculated driving current adjustment, the MCU dynamically adjusts the energizing current of the electromagnetic coil 41, which is currently directly below the mover, through the drive circuit. When the speed deviation exceeds a preset threshold (e.g., ±5 mm / s), the MCU increases or decreases the current value to quickly converge the actual speed to the target speed; when the speed deviation is within the threshold range, the current value is maintained to keep the speed constant.

[0108] When the MCU determines from the position signal that the mover has entered the stroke range corresponding to the deceleration buffer stage, it executes the reverse braking control strategy. The MCU calculates in real time the distance between the current position of the mover and the end of the stroke (i.e., the position where the piston 22 moves to the front end of the medicine tube and the medicine is completely discharged). When this distance is less than the preset deceleration start threshold (e.g., 5mm), the reverse braking control is activated.

[0109] The MCU controls the electromagnetic coil 41, located in front of the moving part, to receive a current in the opposite direction to the driving current. Taking the moving part currently corresponding to coil #n as an example, the MCU controls coil #n+1 and coil #n+2 (if they exist) to receive a reverse current, generating an electromagnetic force in the opposite direction to the moving part's movement, thus decelerating the moving part.

[0110] The magnitude of the reverse current is dynamically adjusted according to the current speed of the mover. The higher the speed, the larger the reverse current is applied to generate sufficient braking force; as the speed decreases, the reverse current is reduced accordingly. For example, when the current speed of the mover is 200 mm / s, a reverse current of 0.6 A is applied to the front coil; when the speed drops to 100 mm / s, the reverse current is adjusted to 0.3 A; when the speed drops to 20 mm / s (below the preset safe speed), the reverse current is cut off.

[0111] Through the above control, the speed of the mover at the end of its stroke is controlled below the preset safe speed (e.g., 10 mm / s), which effectively avoids rigid impact between the mover and the end of the housing, while ensuring that the liquid can still be smoothly discharged at the end of the injection, avoiding jet interruption or liquid residue caused by sudden deceleration.

[0112] The effects of the above technical solution are as follows:

[0113] By linking and storing injection speed curves with drug administration parameters (drug viscosity, target dose, injection site type), and automatically matching the optimal speed curve based on user-selected parameters, differentiated and precise control of the injection process is achieved. Compared to existing electric needle-free injectors that can only provide a single, non-adjustable injection speed, this embodiment can match a rapid injection curve based on the low viscosity characteristics of insulin, or a stable injection curve based on the medium viscosity characteristics of vaccines, or a low-speed, high-precision curve in intradermal injection scenarios, significantly expanding the clinical application range and personalized drug delivery capabilities of the device.

[0114] By controlling multiple electromagnetic coils 41 to be energized sequentially during the acceleration phase and generating a traveling wave magnetic field, the mover is smoothly accelerated from a stationary state to the target speed. The overlapping design of the energizing sequence of adjacent coils ensures that the mover is always subjected to continuous electromagnetic thrust during the switching process, avoiding the problems of insufficient thrust and slow start-up response in the initial stage of the stroke of a traditional single electromagnetic coil 41. This ensures that the jet has sufficient kinetic energy at the moment of skin penetration, guaranteeing the effectiveness of drug delivery.

[0115] By introducing position feedback and PID closed-loop control during the constant-rate injection phase, real-time monitoring and dynamic adjustment of the mover speed are achieved. When the piston resistance changes due to batch differences in the drug tubing, fluctuations in drug viscosity, or changes in ambient temperature, the PID controller can automatically adjust the current of the solenoid coil 41 to compensate for the impact of resistance changes on the speed, ensuring that the actual injection speed strictly follows the target speed curve. This significantly improves the repeatability and consistency of injection doses under different drug tubing conditions and usage conditions, meeting the clinical requirements for long-term precise drug delivery scenarios such as insulin.

[0116] By controlling the electromagnetic coil 41 in front of the mover to pass a reverse current during the deceleration and buffering phase, an active braking force is generated, which enables the mover to effectively decelerate before the end of its journey and finally reach the end at a safe speed. This avoids the impact noise and structural wear caused by the high-speed impact of the mover on the housing 1, and improves the service life of the equipment. It also eliminates the residual medicine or sudden pressure change at the end of the injection caused by inertial impact, ensuring that all medicine is injected smoothly. The dynamic adjustment mechanism of the reverse braking force can adaptively adjust the braking force according to the current speed, realize the smoothness of the deceleration process, and avoid the end speed fluctuation caused by excessive or insufficient braking force.

[0117] The injection process is divided into three stages: acceleration, constant-speed injection, and deceleration buffer. Combined with dedicated control strategies for each stage (traveling wave magnetic field acceleration, PID constant-speed closed-loop, and reverse braking deceleration), a complete closed-loop control system for the injection process is formed. This system allows the syringe to be flexibly configured with speed curves for different drug delivery scenarios, while ensuring a high degree of consistency between the actual execution process and the preset curve, achieving a technological leap from controllable to precisely controllable.

[0118] In one possible implementation, the control component is further configured as follows:

[0119] In the reverse braking control, when the microcontroller determines that the current speed of the mover has dropped below the preset safe speed and the remaining travel is still greater than zero, it controls all electromagnetic coils 41 to be de-energized, allowing the mover to complete the remaining travel by inertia; or

[0120] At least one electromagnetic coil 41 behind the moving part is supplied with a positive current to generate a small thrust in the same direction as the moving part, so that the moving part can complete the remaining journey at the safe speed.

[0121] During the execution of reverse braking control, the control component is further configured with a refined processing mechanism at the end of the braking phase to deal with scenarios where the mover speed has dropped below the safe speed but the remaining travel distance has not yet been completed.

[0122] When the microcontroller unit (MCU) continuously monitors and detects that the current speed of the mover has dropped below a preset safe speed (e.g., 10 mm / s), and determines that the remaining travel is still greater than zero based on the position signal, the MCU executes one of the following two strategies according to the preset end-processing mode:

[0123] Strategy A: Inertial gliding mode, the MCU controls all electromagnetic coils 41 to be de-energized, so that the mover and push rod rely on inertia to complete the remaining stroke.

[0124] For example, in a subcutaneous insulin injection scenario, the preset safe speed is 10 mm / s. When the reverse braking control decelerates the mover speed from 200 mm / s to 10 mm / s, the MCU detects that the remaining stroke is 1.2 mm and the mover speed has stabilized below 10 mm / s (e.g., 9.5 mm / s). At this point, the MCU immediately cuts off the power supply to all electromagnetic coils 41. Since the total mass of the mover and push rod system is relatively small (approximately 15 g), and the sliding friction between the piston and the tube wall inside the drug tube 21 is essentially constant, the mover continues to move forward by inertia at a speed of approximately 9.5 mm / s, reaching the end of its stroke after approximately 0.13 seconds. During the inertial gliding, due to the absence of electromagnetic interference, the mover's motion is entirely dominated by mechanical inertia, and the speed naturally decays, but the decay is small, ensuring that the remaining drug is smoothly injected.

[0125] Strategy B: Uniform speed propulsion mode. The MCU controls at least one electromagnetic coil 41 located behind the moving part to pass a positive current, generating a small thrust in the same direction as the moving part, so that the moving part can complete the remaining journey at a safe and uniform speed.

[0126] For example, in a vaccine intramuscular injection scenario (where the drug solution has high viscosity and requires a stable injection pressure), when the reverse braking control reduces the mover speed to a preset safe speed of 10 mm / s and the remaining stroke is 2.0 mm, the MCU initiates a constant-speed propulsion mode. The MCU determines from the position signal that the mover currently corresponds to coil #n. At this time, a positive current of 0.1 A is applied to control coil #n-1 (the coil behind the mover), generating a small positive thrust of approximately 0.3 N. This thrust is pre-calibrated to overcome the sliding friction between the piston and the drug delivery tube wall (approximately 0.25 N), allowing the mover to advance at a constant speed of 10 mm / s. The MCU continuously monitors the mover speed via the position signal. If the speed fluctuates, the PID controller fine-tunes the current in the rear electromagnetic coil 41 to maintain a constant speed until the mover reaches the end of its stroke and is then de-energized.

[0127] The switching between the two modes can be preset by the operator through the human-machine interface, or automatically selected by the MCU based on the drug administration parameters. For example, for low-viscosity drugs such as insulin, the inertial gliding mode can be selected to simplify control; for high-viscosity drugs or scenarios requiring high consistency of injection pressure, the uniform speed propulsion mode can be selected to ensure the smoothness of the drug discharge at the end.

[0128] The effects of the above technical solution are as follows:

[0129] Once the mover speed has dropped to a safe range, the power supply to all electromagnetic coils 41 is cut off, eliminating the need for complex current regulation. This reduces the computational load on the MCU and the operating frequency of the drive circuit, which helps to reduce system power consumption.

[0130] After power is cut off, the electromagnetic drive component 4 no longer generates an alternating magnetic field, eliminating potential electromagnetic interference to the position detection component (such as a Hall sensor array) and improving the stability and accuracy of position detection.

[0131] During inertial gliding, the motioner's speed naturally decays without sudden electromagnetic force changes, avoiding minor speed fluctuations that may be introduced by current switching, resulting in a smoother discharge of the drug at the injection end.

[0132] The uniform speed propulsion mode combined with position feedback closed-loop control can accurately control the time and position of the mover reaching the end of its stroke, effectively avoiding the uncertainty of the end position caused by inertial gliding and improving the thoroughness of dose emptying.

[0133] The coexistence of the two modes provides operators or MCUs with flexible options, allowing them to select the most suitable end-treatment method based on the viscosity, dosage, and injection site requirements of the specific drug, thus achieving personalized injection control.

[0134] In one possible implementation, the control component is further configured as follows:

[0135] During the deceleration and buffering phase, the microcontroller also determines whether the mover has experienced speed overshoot at the end of its stroke based on the position signal.

[0136] If a speed overshoot is detected, at least one electromagnetic coil 41 located at the end of the stroke is controlled to generate a reverse locking magnetic field to apply a reverse holding force to the mover until the mover speed returns to zero.

[0137] During the deceleration and buffering phase, the MCU continuously monitors the position and speed information of the mover. When the mover reaches the end of its stroke, the MCU determines whether the mover has touched or exceeded the end of its stroke based on the position signal. Specifically, the MCU compares the absolute position fed back by the position detection component with a preset end-of-stroke position threshold: if the mover position is greater than or equal to the end-of-stroke threshold and the current speed is still greater than zero, it is determined that speed overshoot has occurred.

[0138] For example, under certain abnormal operating conditions (such as a sudden decrease in the resistance of the cartridge piston or a momentary response delay in the reverse brake coil drive circuit), the mover approaches the end of its stroke at a speed of 15 mm / s. When the mover reaches the end of its stroke, due to inertia, the mover and push rod continue to move forward at a certain speed, which may impact the end of the housing or cause an impact on the cartridge 21.

[0139] When the MCU detects a speed overshoot, it immediately executes reverse locking magnetic field control:

[0140] The MCU controls at least one electromagnetic coil 41 located at the end of the travel path to generate a reverse locking magnetic field. Specifically, based on the current position of the mover, the MCU selects the electromagnetic coil 41 corresponding to the magnetic coupling part 422 of the mover (or the coil closest to the end of the travel path) and applies a reverse current opposite to the direction of the mover's movement. The magnitude of the current is dynamically determined based on the overshoot speed. For example, when the overshoot speed is 15 mm / s, the MCU controls the coil to apply a 0.5A reverse current, generating an electromagnetic force opposite to the direction of the mover's movement, thus applying a reverse holding force to the mover. This reverse holding force continues to act until the mover's speed returns to zero.

[0141] After the speed reaches zero, the MCU can further control the coil to maintain a small current (e.g., 0.05A) to generate a locking force, keeping the mover at the end of its stroke and preventing it from retracting due to subsequent vibration or external forces. For example, after injection, the MCU controls the coil at the end point to receive a 0.05A reverse current, maintains it for 200ms, and then cuts off the current after the operator removes the syringe from the skin.

[0142] If the overshoot speed is large (e.g., exceeding 20 mm / s), the MCU can simultaneously control multiple electromagnetic coils 41 near the endpoint to supply reverse current, forming a stronger reverse locking magnetic field to ensure that the mover can be effectively braked. For example, simultaneously controlling coil #n and coil #n-1 to supply 0.6A of reverse current generates a superimposed reverse electromagnetic force, quickly reducing the mover speed to zero.

[0143] The effects of the above technical solution are as follows:

[0144] By applying a reverse holding force to the over-impacting rotor using a reverse locking magnetic field, the rotor is effectively prevented from impacting the end of the casing or the tip of the syringe at a non-zero velocity. This avoids damage to the casing structure, the push rod connection 423, and the syringe assembly caused by the mechanical stress generated by the impact, significantly extending the service life of the syringe.

[0145] The overshoot protection mechanism ensures that the mover's speed returns to zero and remains locked at the end of its stroke, preventing it from retracting due to rebound or vibration. If the mover retracts at the end of its stroke, it may cause negative pressure to form inside the drug tube 21, drawing back some of the discharged drug solution and resulting in insufficient actual dosage. By maintaining the mover at the end position through the locking force, this risk is completely eliminated, ensuring dosage accuracy.

[0146] In one possible implementation, the control component is further configured as follows:

[0147] During the injection operation, the electromagnetic coil 41 number corresponding to the magnetic coupling part 422 of the mover is determined based on the position signal;

[0148] When driving the mover to perform the injection action, the electromagnetic coil 41 currently corresponding to the magnetic coupling part 422 and at least one electromagnetic coil 41 adjacent to it along the direction of motion are simultaneously energized to form a magnetic field superposition area.

[0149] Based on the preset injection speed curve and the position signal, the magnitude of the thrust on the magnetic coupling part 422 is adjusted in real time by adjusting the total magnetic flux of the magnetic field superposition area, so that the deviation between the actual movement speed of the push rod 3 and the preset injection speed curve is kept within a preset range.

[0150] The step of adjusting the total magnetic flux of the magnetic field superposition region includes: the microcontroller determining the required thrust adjustment amount based on the deviation between the current speed and the target speed; determining the required magnetic flux increment of the magnetic field superposition region based on the thrust adjustment amount; and adjusting the magnitude of the current flowing through each electromagnetic coil 41 in the magnetic field superposition region and / or the number of electromagnetic coils 41 participating in forming the magnetic field superposition region to make the total magnetic flux of the magnetic field superposition region reach the required value.

[0151] The step of adjusting the current flowing through each electromagnetic coil 41 within the magnetic field superposition region to achieve the desired total magnetic flux in the region includes:

[0152] The microcontroller determines the magnetic coupling efficiency coefficient of each electromagnetic coil 41 based on the relative positional relationship between the magnetic coupling part 422 and each participating electromagnetic coil 41; wherein, the magnetic coupling efficiency coefficient is obtained through pre-calibration and reflects the coupling efficiency between each electromagnetic coil 41 and the magnetic coupling part 422;

[0153] Using the current flowing through each electromagnetic coil 41 as a variable, and with the total magnetic flux in the superposition region of the magnetic fields equal to the required value as a constraint, and in conjunction with the upper limit of the rated current of each electromagnetic coil 41, the distribution value of the current flowing through each electromagnetic coil 41 is solved.

[0154] According to the allocation value obtained from the solution, the corresponding current is supplied to each participating electromagnetic coil 41 through the driving circuit.

[0155] The current distribution values ​​for each electromagnetic coil 41 are determined using one of the following methods:

[0156] Proportional distribution method: The current flowing through each participating electromagnetic coil 41 is the same. The microcontroller calculates the current value of each coil based on the ratio of the required total magnetic flux to the sum of the magnetic coupling efficiency coefficients of each coil. This method is simple to calculate and is suitable for scenarios with high response speed requirements.

[0157] Optimal efficiency allocation method: The microcontroller takes the minimum total power consumption of each electromagnetic coil 41 as the objective function and the required total magnetic flux as the constraint condition to solve the current allocation value of each coil;

[0158] Center of gravity matching allocation method: The microcontroller allocates the current value of each coil according to the position ratio of the magnetic coupling part 422 within the coverage area of ​​each participating electromagnetic coil 41, so that the center of gravity of the magnetic flux density in the magnetic field superposition area is aligned with the center of the magnetic coupling part 422; this method can maximize thrust efficiency and avoid additional torque or radial force caused by the offset of the magnetic field center of gravity.

[0159] In one possible implementation, adjusting the number of electromagnetic coils 41 participating in forming the magnetic field superposition region to achieve the desired total magnetic flux in the magnetic field superposition region includes:

[0160] The microcontroller has multiple preset thrust levels, and each thrust level corresponds to a number of participating electromagnetic coils 41;

[0161] When the required thrust adjustment exceeds the maximum adjustment range that the current gear can provide, the microcontroller adds an electromagnetic coil 41 to switch to a higher thrust gear.

[0162] When the required thrust adjustment is lower than the minimum adjustment range that the current gear can provide, the microcontroller reduces one participating electromagnetic coil 41 and switches to a lower thrust gear.

[0163] In scenarios requiring significant thrust adjustment, the MCU switches thrust levels by changing the number of coils involved in forming the magnetic field superposition region.

[0164] For example, the MCU presets three thrust levels: Basic (one coil is energized, i.e., only the current corresponding coil is energized), Enhanced (two coils form an overlapping area), and Powerful (three coils form an overlapping area). The thrust-current characteristic curves of each level are calibrated experimentally.

[0165] For example, during the acceleration phase, when the required thrust exceeds the maximum output capacity of the enhanced mode at the rated current, the MCU switches to the powerful mode, controlling coils #n, #n+1, and #n+2 to be energized simultaneously, forming a three-coil superposition area. At this time, even if the current of each coil remains below the rated value, the total thrust can still meet the acceleration requirements.

[0166] During acceleration, as the mover speed gradually approaches the target speed, the required thrust gradually decreases. When the thrust requirement drops below the maximum output capability of the enhanced mode, the MCU switches back to the enhanced mode, reducing one participating coil to lower energy consumption.

[0167] In one possible implementation, the control component is further configured as follows:

[0168] During the acceleration phase of the injection operation, multiple electromagnetic coils 41 are sequentially controlled to form magnetic field superposition regions along the direction of motion, and the number of electromagnetic coils 41 contained in each magnetic field superposition region gradually increases to achieve a gradient increase in thrust; or

[0169] During the deceleration and buffering phase of the injection operation, multiple electromagnetic coils 41 are sequentially formed along the direction of motion to create a magnetic field superposition area, and the number of electromagnetic coils 41 contained in each magnetic field superposition area gradually decreases to achieve a gradient reduction in thrust.

[0170] During the acceleration phase of the injection operation, the MCU controls the formation of multiple magnetic field superposition zones along the direction of motion, and the number of electromagnetic coils 41 contained in each superposition zone gradually increases, thereby achieving a gradient increase in thrust.

[0171] For example, at the initial moment of the acceleration phase (t=0), the mover is in position #1 of coil #1. The MCU controls coil #1 to be energized alone (one coil superposition area), generating a basic thrust F0 to propel the mover forward. When the mover moves to the boundary area between coil #1 and coil #2, the MCU controls coil #1 and coil #2 to be energized simultaneously (two coil superposition areas), increasing the thrust to approximately 1.8F0. As the mover continues forward, when it fully enters coil #2, the MCU controls coil #2 and coil #3 to be energized simultaneously, maintaining the two coil superposition areas. When the mover moves to near the end of the acceleration phase, the MCU controls coils #2, #3, and #4 to be energized simultaneously (three coil superposition areas), increasing the thrust to approximately 2.4F0 to overcome inertia and complete the final acceleration.

[0172] During the deceleration and buffering phase, the MCU employs a reverse gradient reduction strategy. In the initial deceleration phase, the MCU controls three coil superimposed areas to generate a strong reverse braking force; as the speed decreases, it gradually switches to two coil superimposed areas, then one coil superimposed area, and finally relies solely on inertial gliding to achieve smooth deceleration.

[0173] The effects of the above technical solution are as follows:

[0174] By forming a magnetic field superposition region and adjusting the number of coils and current within the superposition region, the thrust adjustment range is significantly expanded. For example, the maximum thrust of a single electromagnetic coil 41 at rated current is F_max, while using two coil superposition regions can increase the thrust to 1.6-1.8F_max, and using three coil superposition regions can increase it to 2.2-2.5F_max. This allows the solution to adapt to a wide range of drug delivery scenarios, from low viscosity and small dose (low thrust required) to high viscosity and large dose (high thrust required), without increasing the coil volume or the rated current.

[0175] By finely adjusting the current distribution of each coil within the magnetic field superposition region, stepless adjustment of thrust can be achieved within a continuous range. Compared to a single electromagnetic coil 41, which can only change thrust by adjusting the current, this scheme adds the additional adjustment dimension of the number of participating coils. This is equivalent to adding a frequency multiplication effect on the basis of the original adjustment resolution, making thrust control more precise, speed deviation convergence faster, and steady-state error smaller.

[0176] During the acceleration phase, a gradient-increasing coil number strategy is employed, causing the thrust to gradually increase with the mover speed. This matches the gradually increasing acceleration requirement in the injection velocity curve, avoiding the abrupt acceleration changes caused by a single constant thrust in traditional schemes. During the deceleration phase, a gradient-decreasing strategy is used, causing the braking force to gradually decrease with the speed reduction, achieving smooth deceleration and avoiding sudden speed drops or inertial overshoot due to excessive braking force. This gradient control strategy significantly improves the accuracy of velocity curve tracking.

[0177] The center-of-gravity matching distribution method ensures that the center of gravity of the magnetic flux density in the magnetic field superposition area is aligned with the center of the magnetic coupling part 422, so that the electromagnetic force acts evenly on the magnetic coupling part 422, avoiding the radial component force caused by the offset of the magnetic field center of gravity. The radial component force will increase the friction between the mover and the inner wall of the coil, reduce the transmission efficiency and accelerate wear. By eliminating the radial component force, this solution improves the conversion efficiency of electromagnetic energy to mechanical energy and extends the service life of the equipment.

[0178] The optimal efficiency allocation method minimizes the total power consumption of the coils while meeting the thrust requirements. Taking the overlapping area of ​​two coils as an example, the current of the equal allocation method is I0, and the total power consumption is 2I0²R. The optimal efficiency allocation method reduces the total power consumption by allocating more current to the coil with higher magnetic coupling efficiency (i.e., the coil closer to the center of the magnetic coupling part 422). For battery-powered portable needle-free injectors, this means a longer number of uses per charge.

[0179] The dynamic adjustment of the magnetic field superposition zone is entirely based on real-time feedback from position signals and velocity curves, forming a complete closed-loop control chain encompassing position detection, velocity deviation calculation, thrust adjustment determination, magnetic flux adjustment, and coil current / number adjustment. This ensures a high degree of consistency between the actual motion speed and the preset velocity curve throughout the entire injection stroke, providing technical support for precise dosage control and personalized drug delivery.

[0180] Example 2:

[0181] See attached document Figure 3 This embodiment provides a control method for an intelligent electric needle-free injector, applicable to the intelligent electric needle-free injector in Embodiment 1, including the following steps:

[0182] The control component receives the target dose command and calculates the target displacement of push rod 3 based on the target dose.

[0183] In the drug inhalation mode, the control component controls the plurality of electromagnetic coils 41 through the drive circuit to generate electromagnetic force in the first direction, driving the mover and push rod 3 to move backward.

[0184] In injection mode, the control component controls the plurality of electromagnetic coils 41 through the drive circuit to generate an electromagnetic force in a second direction opposite to the first direction, driving the mover and push rod 3 to move forward.

[0185] The control component continuously receives the position signal from the position detection component and adjusts the control of the electromagnetic coil 41 in real time according to the position signal, forming a closed-loop control of the displacement and / or speed of the push rod 3.

[0186] The control of the electromagnetic coil 41, adjusted in real time according to the position signal, includes:

[0187] Obtain a preset injection speed curve, which includes at least an acceleration phase, a constant speed injection phase, and a deceleration buffer phase.

[0188] The travel range of the moving part is determined based on the position signal;

[0189] During the acceleration phase, the plurality of electromagnetic coils 41 are sequentially energized along the direction of motion of the mover to generate a traveling wave magnetic field to accelerate the mover.

[0190] When in the constant speed injection stage, the current speed is calculated in real time based on the position signal, and the closed-loop control algorithm is used to dynamically adjust the current of the electromagnetic coil 41 that is currently aligned with the mover in the direction of motion in order to maintain a constant speed.

[0191] When in the deceleration and buffering phase, the electromagnetic coil 41 located in front of the mover along the direction of the mover's movement is energized to generate a reverse braking force, causing the mover and push rod 3 to decelerate before the end of the stroke.

[0192] The working principle and beneficial effects of the above technical solution are the same as those in Example 1, and will not be repeated here.

[0193] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A smart electric needle-free injector, characterized in that, include: Shell (1); The drug tube assembly includes a drug tube (21) for containing liquid medicine and a piston (22) slidably disposed within the drug tube (21). The push rod (3) is connected to the piston (22); The electromagnetic drive assembly (4) is disposed in the housing (1) and includes a mover fixedly connected to the push rod (3) and a stator arranged around the mover and along its direction of motion. The stator includes a plurality of independently controllable electromagnetic coils (41) for generating electromagnetic force when energized to drive the mover to make linear motion. A position detection component is used to detect the absolute position of the push rod (3) or the mover in real time and generate a position signal; The control component includes a microcontroller unit and a drive circuit. The control component is configured to independently control the energizing state of the plurality of electromagnetic coils (41) according to the target dose and the position signal, so as to drive the mover to perform drug aspiration or injection operations.

2. The intelligent electric needleless injector according to claim 1, characterized in that, The stator includes at least three independently controllable electromagnetic coils (41) arranged equidistantly along the axial direction. The electromagnetic coils (41) are isolated from each other by insulating spacers (5), and the energizing state of each electromagnetic coil (41) is independently controlled by the drive circuit.

3. The intelligent electric needleless injector according to claim 1, characterized in that, The mover has a stepped cylindrical structure, including a guide part (421) with a first diameter at the front end, a magnetic coupling part (422) with a second diameter in the middle, and a connecting part (423) with a third diameter at the rear end. There is an air gap of 0.1-0.5mm between the outer diameter of the magnetic coupling part (422) and the inner diameter of the electromagnetic coil (41). The mover and the push rod (3) are integrally formed or fixedly connected, wherein the second diameter > the third diameter > the first diameter.

4. The intelligent electric needleless injector according to claim 1, characterized in that, The position detection assembly includes a magnetostrictive displacement sensor with a waveguide wire extending along the axial direction of the push rod (3) and a position magnet disposed on the mover.

5. The intelligent electric needleless injector according to claim 1, characterized in that, The position detection component includes an array of linear Hall sensors arranged along the axial direction and a permanent magnet disposed on the mover. The microcontroller calculates the absolute position of the push rod (3) by detecting the position of the permanent magnet through the Hall sensor array.

6. The intelligent electric needleless injector according to claim 1, characterized in that, The control component is also configured to: A preset injection speed curve is obtained during the injection operation, and the injection speed curve includes at least an acceleration phase, a constant speed injection phase, and a deceleration buffer phase. The travel range of the moving part is determined based on the position signal; When in the acceleration phase, the plurality of electromagnetic coils (41) are energized sequentially along the direction of motion of the mover to generate a traveling wave magnetic field to accelerate the mover; When in the constant speed injection stage, the current speed is calculated in real time according to the position signal, and the closed-loop control algorithm is used to dynamically adjust the current of the electromagnetic coil (41) that is currently aligned with the mover in the direction of motion in order to maintain a constant speed. When in the deceleration buffer phase, the electromagnetic coil (41) located in front of the mover along the direction of the mover's movement is energized to generate a reverse braking force, so that the mover and push rod (3) decelerate before the end of the stroke.

7. The intelligent electric needleless injector according to claim 3, characterized in that, The control component is also configured to: During the injection operation, the electromagnetic coil (41) number currently corresponding to the magnetic coupling part (422) of the mover is determined based on the position signal; When the actuator is driven to perform the injection action, an electromagnetic coil (41) currently corresponding to the magnetic coupling part (422) and at least one electromagnetic coil (41) adjacent to it along the direction of motion are simultaneously energized to form a magnetic field superposition area. Based on the preset injection speed curve and the position signal, the magnitude of the thrust on the magnetic coupling part (422) is adjusted in real time by adjusting the total magnetic flux of the magnetic field superposition area, so that the deviation between the actual movement speed of the push rod (3) and the preset injection speed curve is kept within the preset range.

8. The intelligent electric needle-free injector according to claim 7, characterized in that, The control component is also configured to: During the acceleration phase of the injection operation, multiple electromagnetic coils (41) are sequentially arranged along the direction of motion to form magnetic field superposition zones, and the number of electromagnetic coils contained in each magnetic field superposition zone gradually increases to achieve a gradient increase in thrust; or During the deceleration and buffering phase of the injection operation, multiple electromagnetic coils (41) are sequentially formed along the direction of motion to create a magnetic field superposition zone. The number of electromagnetic coils (41) contained in each magnetic field superposition zone gradually decreases to achieve a gradient reduction in thrust.

9. A control method for an intelligent electric needleless injector according to any one of claims 1-8, characterized in that, Includes the following steps: The control component receives the target dose command; and calculates the target displacement of the push rod (3) based on the target dose. In the drug inhalation mode, the control component controls the plurality of electromagnetic coils (41) through the drive circuit to generate electromagnetic force in the first direction, driving the mover and push rod (3) to move backward; In injection mode, the control component controls the plurality of electromagnetic coils (41) through the drive circuit to generate an electromagnetic force in a second direction opposite to the first direction, driving the mover and push rod (3) to move forward; The control component continuously receives the position signal from the position detection component and adjusts the control of the electromagnetic coil (41) in real time according to the position signal to form a closed-loop control of the displacement and / or speed of the push rod (3).

10. The control method for the intelligent electric needleless injector according to claim 9, characterized in that, The real-time adjustment of the control of the electromagnetic coil (41) based on the position signal includes: Obtain a preset injection speed curve, which includes at least an acceleration phase, a constant speed injection phase, and a deceleration buffer phase. The travel range of the moving part is determined based on the position signal; When in the acceleration phase, the plurality of electromagnetic coils (41) are energized sequentially along the direction of motion of the mover to generate a traveling wave magnetic field to accelerate the mover; When in the constant speed injection stage, the current speed is calculated in real time according to the position signal, and the closed-loop control algorithm is used to dynamically adjust the current of the electromagnetic coil (41) that is currently aligned with the mover in the direction of motion in order to maintain a constant speed. When in the deceleration buffer phase, the electromagnetic coil (41) located in front of the mover along the direction of the mover's movement is energized to generate a reverse braking force, so that the mover and push rod (3) decelerate before the end of the stroke.

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