Research And Design Of Needle-free Injector

Although traditional needle injection is convenient for us, but some problems are brought in by injection, for example, subcutaneous protuberance by injecting for long time, needle pricking, pain, needle fear, spread disease by using needle repeatedly and so on. In order to solve these problems, needlefree injecting technique is developed gradually. Needlefree injection bring many advantages, such as painless injecting, good medicine imbibitions, non-cross infection, self-injecting. In this paper, a needlefree injector based on the power of high stiffness spring is proposed, and a prototype is developed to do some medical experiments for further research.Firstly, based the general situation of domestic and foreign needlefree injector, analyse needlefree injecting mechanics, analyse the characteristic of various structures of needlefree injecton, fulfill the system integer design. Choose the spring as power ,design the separate structure between injecting head and power head.Secondly, built injecting procedure mathmatic model of needlefree injection, analyse the influence of power head structural parameters on injecting pressure. Design the power spring reference on"Injex"needlefree injector, based on the size of spring design the structure of power head.Thirdly, design injecting head and related auxiliary units with needlefree injection, including spring compressing device, taking medicine adapter. Design and improve a trigger device located on the top of injector, made power head prototype, and made springs of three different stiffness to do experiments.Last, according to the experiments, analyse the designed needlefree injector and propose the further improved scheme.All the above show that the designed needlefree injector driven by proper stiffness spring can reach the application level of the common"Injex"needlefree injector in market.