大剂量多孔无针注射器结构优化

Structure Optimization of Large Dose Multi-hole Needle-free Injector

针对目前单孔无针注射器单次注射剂量小、需要多次重复注射的缺陷,提出一种大剂量多孔无针注射器.应用ANSYS Workbench仿真平台对多孔无针注射器的注射流场进行分析,发现多孔无针注射器的工作压力不低于13 MPa;并通过流固耦合分析,得到多孔无针注射器不同直径的应力变化规律,且拟合了不同压力下许用应力与最小安瓿直径之间的关系多项式.根据仿真结果设计正交试验对多孔无针注射器收缩段进行结构优化,得到优化方案:20°收缩角、1.4的长径比、2 mm的分布圆直径、4.05 mm的收缩段长度和0.165 mm的微孔直径.且通过安瓿的应力分析,验证了优化方案满足材料的力学性能要求.优化结果表明,该注射器具有比传统单孔注射器更大的注射剂量,可达5 mL,注射速度高达150 m/s以上,能击穿皮肤,同时又不致造成过多损伤.试验及动力学分析进一步验证了优化方案的可行性.

Aiming at the shortcomings that the single injection dose of the current single-hole needle-free injector is small and requires repeated injections, a large-dose multi-hole needle-free injector is proposed. ANSYS Workbench simulation platform was used to analyze the flow field of the needle-free injector, and the working pressure range was gained not less than 13 MPa. Meanwhile, the stress variation law of the needle-free injector under different diameters was obtained by fluid-structure interaction analysis. The relationship polynomial between the allowable stress and the minimum ampoule diameter under various pressures is fitted. According to the simulation results, an orthogonal test was designed to optimize the structure of the contraction section for the needle-free injector. The optimized scheme was obtained as follows: the contraction angle was 20°, the aspect ratio was 1.4, the diameter of the distribution circle was 2 mm, the contraction section length was 4.05 mm, and the diameter of the micro-hole was 0.165 mm. Through the stress analysis of the ampoule, it is verified that the optimized scheme can meet the mechanical property requirements of the material. The optimization results show that a larger dose is achieved than the traditional single-hole injector, the dose can be up to 5 mL, and the injection speed is as high as 150 m/s, which can penetrate the skin without causing too much damage. The feasibility of the optimization scheme was further verified through experiments and kinetic analysis.