静脉留置针的生物力学建模与实验研究

Biomechanical modeling and experimental research of peripherally inserted venous catheter

目的对静脉留置针进行理论分析与实验研究,建立不同材质留置针导管与模拟皮肤组织相互作用的理论模型,同时对不同留置针导管进行测试,为留置针的优化设计提供理论基础和实验依据。方法根据留置针导管在25℃和37℃下的力学特性,建立导管穿刺模拟皮肤组织的有限元模型,分析穿刺过程中导管褶皱情况与导管材料和结构的关系,并对留置针导管的刚度、X射线显影性等进行实验测试。结果导管在不同温度下的性能与其材料密切相关,导管褶皱情况与导管材料、楔形面倾角有关,聚氨酯(PU)导管在常温(25℃)下的弹性模量约为500 MPa,在体温(37℃)下的弹性模量约为250 MPa,满足穿刺时刚度大、留置时材质软的临床需求。在导管结构相同时,PU导管比氟化乙烯丙烯共聚物(FEP)导管更不易发生褶皱;导管材料相同时,楔形面倾角越小,导管越不易发生褶皱。结论适当减小留置针针头的楔形面倾角,可以提高穿刺成功率。PU导管具有较好的力学特性,其在穿刺时不易发生褶皱,并且在体温时刚度有所降低,既可以提高穿刺成功率,也可以减少并发症的发生,具有更好的临床应用前景。

Objective To conduct theoretical analysis and experimental research on peripherally inserted venous catheters,establish theoretical models of interaction between different materials catheters and simulated skin tissues,and test different catheters at the same time to provide theoretical basis and experimental basis for the optimization design.Methods According to the mechanical properties of the catheter at 25℃and 37℃,a finite element model of the catheter and simulate skin tissue was established.The relationship between catheter folds and material and structure during puncture was analyzed,and the stiffness,radiographic properties,etc.were tested experimentally.Results The performance of the catheter at different temperatures is closely related to its material.The wrinkle situation of the catheter is related to the catheter material and the inclination of the wedge surface.The elastic modulus of the polyurethane(PU)catheter is about 500 MPa and 250 MPa,respectively at room temperature(25℃)and body temperature(37℃),which meets the clinical needs of high rigidity during puncture and soft material during indwelling.When the catheter structure is the same,the PU catheter is less prone to wrinkles than the fluorinated ethylene propylene copolymer(FEP)catheter.When the catheter material is the same,the smaller the inclination of the wedge surface,the less likely the catheter to wrinkle.Conclusions Appropriately reducing the inclination of the wedge-shaped surface of the needle of peripherally inserted venous catheters can improve the success rate of puncture.The PU catheters have good mechanical properties,they are not prone to wrinkles during puncture,and their stiffness can be reduced at body temperature,which can not only increase the success rate of puncture,but also reduce the occurrence of complications.Therefore,PU catheters have a better clinical application prospect.