| In the current medical system,traditional syringes are widely used because of their simple structure and low price.However,the pain caused by the needle piercing the skin and the local damage caused by long-term injection,skin induration and other problems cause many patients to have a "terrorism" phenomenon.And as a disposable,the use of discarded syringes after extensive use has increased the production of "medical waste." However,there are some problems in the existing needle-free syringes.For example,the mechanical needle-free injector has unstable driving force and is difficult to adjust,and the injection stability is poor;the pneumatic needle-free injector has a large overall volume,high noise,low injection efficiency,and voice coil type electromagnetic The needle syringe has a complicated structure.Aiming at these problems,a magnetoresistive electromagnetic energy storage needleless injector was designed and the designed needleless injection device was analyzed.1.By analyzing and comparing various electromagnetic driving methods,a magnetoresistive electromagnetic driving method with simple structure and high efficiency is selected as the needleless injector driving system.According to the selected drive system,the mathematical model is established.Through the magnetic field simulation software Maxwell,the correctness of the theoretical model is verified,and the relationship between current magnitude,core position,core length and diameter and core force is determined.The drive system is determined.The parameters show that the designed drive system can provide 150N driving force;2.Using Matlab to solve the mathematical model of the needle-free injector ampere,the value of the stagnation pressure is 16Mpa.Using Fluent to simulate the jet flow,it is found that the size of the anti-stagnation pressure is similar to that of Matlab.The simulation results of the different structures of the ampoule solution show that the steady rate of the injection of the ampule solution is higher than that of the flat-headed ampoule solution.Simulation of the diffusion effect of the drug solution,it is roughly found that the needle-free injector designed can achieve an injection depth of 5 mm and has a spherical-like diffusion effect;3.Using the simulation results of the designed needle-free injector,design the experimental platform;through the inductance measurement of the coil,it is proved that there is no short circuit or leakage in the produced drive system,the drive system quality is good;the driving force verification,experimental results and simulation The results are similar.The effects of voltage,current and air travel on the output performance of the drive system are investigated by orthogonal experiment.The research shows that the influence of the idle stroke is the largest,and the influence of current and voltage on the driving force is the smallest.Therefore,the air travel is 10mm to realize the energy storage.The current size of 9A and the voltage of 24V are the optimal experimental parameters.The experimental results show that the experimental jet velocity is similar to the simulation results,which further validates the feasibility of the designed needleless injector.4.The structure of needleless syringe was designed as a whole,and the incident process of liquid medicine was explored.The same dose and different gear injection experiments were carried out with pork similar to human skin.It was found that different gear can effectively control the injection depth of the liquid and have certain influence on the diffusion width.At the same time,compared with the effect of no-empty travel injection,it was found that empty travel can effectively increase the injection depth of the liquid and make the liquid completely diffuse at low gear.In the same block and different dosage injection experiments,the injection dose has less effect on the injection depth and greater influence on the diffusion width when the injection dose meets the maximum depth.Finally,the recommended table of injection gear for needle-free injection device is given through experiments.CONCLUSION:An electromagnetic needleless injection device is designed by reluctance electromagnetic drive.The device has the advantages of energy storage,simple structure,safety and controllability,simple and portable.The experimental study shows that it can meet the injection requirements,has good injection effect,and has a certain practicability and feasibility. |
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