新型可注射性人工髓核的生物力学测试

Biomechanical research of a new injectable prosthetic nucleus pulposus

目的:对自行研制的新型可注射性人工髓核进行体外生物力学测试,为其应用于临床提供实验依据。方法:将用聚碳酸酯聚氨酯(PCU)被囊和硅橡胶填充物制备而成的人工髓核在生物力学测试机上进行压缩模量试验、静刚度试验、动刚度试验、屈服极限试验,记录相关数据,并进行相关分析。结果:以10N/s的速度对假体纵向缓慢加载到150N、250N、350N、500N、1000N时人工髓核的应力和应变成非线性关系,弹性模量约为2.5MPa;以10N/s的速度纵向加载到1000N过程中静刚度逐渐增大,且为非线性;以10N/s的速度缓慢纵向加载到400N时,动刚度在0.5～3Hz激振频率范围内其应力滞后于应变的相位角约为13°,在激振频率为3Hz时,动刚度约为静刚度的3.5倍;以10N/s的速度从500N～2000N范围内缓慢加载,填充物没有塑性变形;在1200N时,1个假体发生屈服。结论:新型可注射性人工髓核具有良好的粘弹性,抗形变能力强,可试用于动物体内研究,但材料尚需进一步改进。

Objective：To test the biomechanical features of a new injectable prosthetic nucleus pulposus so as to provide data for clinical practice.Method：The biomechanical test was carried out on prosthetic nucleus pulposus prepared by filling with polyurethane and silicone rubber to explore compression modulus,static stiffness,dynamic stiffness and the yielding limit.The relevant data were recorded and analyzed.Result：When increasing the preload to 150N,250N,350N,500N,1000N with a speed of 10N/s,the stress and strain of prosthetic nucleus pulposus showed a non-linear relationship with the elastic modulus of approximate 2.5MPa. During the process of increasing the preload to 1000N with a speed of 10N/s,the static stiffness increased gradually and demonstrated non-linear feature.During the process of increasing the preload to 400N with a speed of 10N/s,the dynamic stiffness in range of 0.5-3Hz laged behind the stress of the phase angle at about 13 degrees.Dynamic stiffness was about 3.5 times of static stiffness in the frequency of 3Hz.Dufing the process of increasing the preload from 500N to 2000N with a speed of 10N/s,the filler showed no plastic deformation,while at the preload of 1200N,1 prosthetic nucleus pulposus broken.Conclusion：New injectable prosthetic nucleus has good flexibility and toughness ,and it is close to the physiological characteristics of real nucleus pulposus,whieh may be used in animal research,however this material is something to be improved.