Search

CN-122006019-A - Intelligent electric needleless injector and control method

CN122006019ACN 122006019 ACN122006019 ACN 122006019ACN-122006019-A

Abstract

The invention discloses an intelligent electric needleless injector and a control method, relating to the technical field of medical appliances, wherein the injector comprises a shell; the medicine tube assembly comprises a medicine tube and a piston which is slidably arranged in the medicine tube, a push rod which is connected with the piston, an electromagnetic driving assembly which is arranged in a shell and comprises a rotor which is fixedly connected with the push rod and a stator which surrounds the rotor and is arranged along the moving direction of the rotor, wherein the stator comprises a plurality of independent controllable electromagnetic coils, a position detection assembly is used for detecting the absolute position of the push rod or the rotor in real time and generating a position signal, and a control assembly comprises a micro control unit and a driving circuit, the control assembly is configured to independently control the electrifying states of the plurality of electromagnetic coils through the driving circuit according to target doses and the position signal so as to drive the rotor to perform medicine sucking or injection operation, accurate adjustment of injection doses and speeds is achieved, and stability of an injection process and safety of equipment operation are improved.

Inventors

  • ZHANG XIN
  • LIU LI
  • HAO FUXING
  • WU CAIHONG

Assignees

  • 苏州森恩博医疗科技有限公司

Dates

Publication Date
20260512
Application Date
20260327

Claims (10)

  1. 1. An intelligent, electrically powered needleless injector, comprising: A housing (1); a cartridge assembly comprising a cartridge (21) for containing a medical fluid and a piston (22) slidably disposed within the cartridge (21); a push rod (3) connected to the piston (22); The electromagnetic driving assembly (4) is arranged in the shell (1) and comprises a rotor fixedly connected with the push rod (3) and a stator which surrounds the rotor and is arranged along the moving direction of the rotor, and the stator comprises a plurality of independently controllable electromagnetic coils (41) and is used for generating electromagnetic force to drive the rotor to do linear motion when being electrified; The position detection component is used for detecting the absolute position of the push rod (3) or the rotor in real time and generating a position signal; And the control assembly comprises a micro-control unit and a driving circuit, and is configured to independently control the energizing states of the electromagnetic coils (41) through the driving circuit according to the target dosage and the position signal so as to drive the rotor to perform medicine sucking or injection operation.
  2. 2. The intelligent electric needleless injector as in claim 1, in which the stator comprises at least three independently controllable electromagnetic coils (41) arranged axially equidistant, the electromagnetic coils (41) being separated from each other by insulating spacers (5), and each electromagnetic coil (41) being independently controlled by the drive circuit for the energized state.
  3. 3. The intelligent electric needleless injector according to claim 1, wherein the whole rotor is of a stepped cylindrical structure and comprises a guide part (421) with a first diameter at the front end, a magnetic coupling part (422) with a second diameter at the middle part and a connecting part (423) with a third diameter at the rear end, an air gap of 0.1-0.5mm is reserved between the outer diameter of the magnetic coupling part (422) and the inner diameter of the electromagnetic coil (41), and the rotor and the push rod (3) are integrally formed or fixedly connected, wherein the second diameter > the third diameter > the first diameter.
  4. 4. The intelligent electric needleless injector as claimed in claim 1, in which the position detection assembly comprises a magnetostrictive displacement sensor, the waveguide wire of which extends in the axial direction of the push rod (3), and the position magnet of which is provided on the mover.
  5. 5. The intelligent electric needleless injector as claimed in claim 1, in which the position detection assembly comprises a linear hall sensor array arranged in the axial direction, and a permanent magnet provided on the mover, the micro control unit calculating the absolute position of the push rod (3) by detecting the position of the permanent magnet through the hall sensor array.
  6. 6. The intelligent, electrically powered needleless injector of claim 1, wherein the control assembly is further configured to: Acquiring a preset injection speed curve in an injection operation, wherein the injection speed curve at least comprises an acceleration stage, a constant-speed injection stage and a deceleration buffering stage; judging a travel interval where the mover is located based on the position signal; when the rotor is in an acceleration stage, the electromagnetic coils (41) are controlled to be sequentially electrified along the moving direction of the rotor, and a travelling wave magnetic field is generated to accelerate the rotor; When the injection device is in a constant-speed injection stage, the current speed is calculated in real time according to the position signal, and the current energizing current of an electromagnetic coil (41) aligned with the rotor in the motion direction is dynamically regulated by adopting a closed-loop control algorithm so as to maintain the speed constant; When the braking and buffering stage is in, the electromagnetic coil (41) positioned in front of the rotor along the moving direction of the rotor is controlled to be electrified to generate reverse braking force, so that the rotor and the push rod (3) are decelerated before the stroke end point.
  7. 7. The intelligent, electrically powered needleless injector of claim 3, wherein the control assembly is further configured to: Judging the number of the electromagnetic coil (41) corresponding to the magnetic coupling part (422) of the rotor currently according to the position signal in the injection operation; When the rotor is driven to execute injection action, controlling one electromagnetic coil (41) corresponding to the magnetic coupling part (422) and at least one electromagnetic coil (41) adjacent to the electromagnetic coil along the movement direction to be electrified simultaneously so as to form a magnetic field superposition area; and according to a preset injection speed curve and the position signal, the magnitude of the thrust to 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.
  8. 8. The intelligent, electrically powered needleless injector of claim 7, wherein the control assembly is further configured to: in the acceleration stage of injection operation, a plurality of electromagnetic coils (41) are controlled to sequentially form magnetic field superposition areas along the movement direction, and the number of the electromagnetic coils contained in each magnetic field superposition area is gradually increased so as to realize gradient increment of thrust force, or In the deceleration buffering stage of injection operation, a plurality of electromagnetic coils (41) are controlled to sequentially form magnetic field superposition areas along the movement direction, and the number of the electromagnetic coils (41) contained in each magnetic field superposition area is gradually reduced so as to realize gradient decrease of thrust.
  9. 9. A control method for the intelligent electric needleless injector of any of claims 1 to 8, comprising the steps of: the control component receives a target dose instruction, calculates target displacement of the push rod (3) according to the target dose; In the drug sucking mode, the control component controls the electromagnetic coils (41) through the driving circuit to generate electromagnetic force in a first direction, and drives the mover and the push rod (3) to move backwards; in an injection mode, the control assembly controls the plurality of electromagnetic coils (41) through the driving circuit to generate electromagnetic force in a second direction opposite to the first direction, and drives the mover and the push rod (3) to move forwards; The control assembly continuously receives the position signal from the position detection assembly and adjusts the control of the electromagnetic coil (41) in real time according to the position signal, so that closed-loop control of the displacement and/or the speed of the push rod (3) is formed.
  10. 10. The method of controlling an intelligent electric needleless injector as claimed in claim 9, in which the adjusting of the control of the electromagnetic coil (41) in real time in accordance with the position signal comprises: Acquiring a preset injection speed curve, wherein the injection speed curve at least comprises an acceleration stage, a constant-speed injection stage and a deceleration buffering stage; Judging a travel interval where the mover is located according to the position signal; when the rotor is in an acceleration stage, the electromagnetic coils (41) are controlled to be sequentially electrified along the moving direction of the rotor, and a travelling wave magnetic field is generated to accelerate the rotor; When the injection device is in a constant-speed injection stage, the current speed is calculated in real time according to the position signal, and the current energizing current of an electromagnetic coil (41) aligned with the rotor in the motion direction is dynamically regulated by adopting a closed-loop control algorithm so as to maintain the speed constant; When the braking and buffering stage is in, the electromagnetic coil (41) positioned in front of the rotor along the moving direction of the rotor is controlled to be electrified to generate reverse braking force, so that the rotor and the push rod (3) are decelerated before the stroke end point.

Description

Intelligent electric needleless injector and control method Technical Field The invention relates to the technical field of needleless injectors in the field of medical appliances, in particular to an intelligent electric needleless injector and a control method. Background Needleless injection technology is a mode of administration that delivers a medical fluid through the surface layer of the skin to the intradermal, subcutaneous or intramuscular tissue by high pressure jet without the aid of a needle. Compared with the traditional needle injection, the needleless injection has the remarkable advantages of eliminating needle phobia, avoiding needle puncture, reducing cross infection risk, improving medicine absorptivity, improving patient compliance and the like, and has wide application prospect in the fields of insulin, growth hormone, vaccine, large-scale immunization and the like. The existing needleless injectors are mainly divided into three types, namely spring energy storage type, pneumatic type and electric type. The spring energy storage type needleless injector stores mechanical energy by manually compressing a spring, and the spring is instantly released to push a piston to realize injection after triggering. The structure completely depends on mechanical transmission, and has the inherent defects that firstly, the output force of the spring is attenuated along with the increase of the travel, the stable pressure is difficult to maintain in the whole injection process, the insufficient jet kinetic energy or the excessive residual energy is caused, the drug delivery depth and the distribution uniformity are influenced, secondly, the compression travel of the spring and the lack of accurate quantitative corresponding relation of injection dose are required to be manually set by an operator, the dose control precision is low, the requirement of a small dose or high-precision dosing scene is difficult to be met, thirdly, the manual force accumulation is required before each injection, the operation is complicated, the operation consistency is poor according to the individual, and fourthly, the spring is easy to generate fatigue deformation, the output force is gradually attenuated and the equipment performance is unstable after long-term use. Pneumatic needleless injectors utilize high pressure gas (e.g., carbon dioxide cylinders or compressed air) as a power source and control the release of gas through a gas valve to push a piston. Although the injector can realize higher injection speed and relatively stable output, the injector has a complex structure, large equipment volume and weight and poor portability, is usually required to be provided with a gas cylinder or an external gas source, has obvious influence on gas pressure due to environmental temperature, reduces gas pressure in a low-temperature environment, is difficult to ensure consistency of injection depth, and has the advantages that the gas cylinder belongs to a pressure container, is limited in transportation and storage and has higher use cost. With the development of electromagnetic technology, some electric needleless injector solutions have emerged in recent years. The existing electric needleless injector generally adopts an electromagnetic driving structure, and electromagnetic force is generated by electrifying to drive a push rod to realize injection. However, such schemes still have the following technical limitations in practical applications: First, the controllability of the driving force is insufficient. In the whole motion stroke of the push rod, the output force characteristic of the existing electromagnetic driving structure is difficult to keep stable and controllable, and particularly in different stages of the stroke, the driving force often shows non-uniform change, so that insufficient thrust establishment in the initial stage of injection or energy overshoot occurs in the final stage of injection, and the stability and consistency of drug delivery are affected. Second, the dynamic regulation of the injection process is lacking. Most of the existing schemes can only realize simple start-stop control, are difficult to finely adjust the movement speed and displacement of the push rod, cannot carry out differential programming according to the drug characteristics (such as viscosity and dosage) or the injection position requirements (intradermal, subcutaneous or intramuscular), and are difficult to meet the requirements of personalized drug administration. Third, the accuracy of dose control is limited by the open loop approach. The existing scheme lacks a real-time sensing and dynamic regulating mechanism for the motion state of the push rod, dose control usually depends on an open loop mode, when a medicine tube is replaced, piston resistance changes or medicine liquid viscosity fluctuates, deviation is easy to generate between the actual injection quantity and the set dose, and the dose repeatability and the ac