生物软组织超弹性及夹持过程仿真分析

目的确定生物软组织的超弹性本构方程,并在此基础上研究生物组织夹持过程的力学响应规律。方法以新鲜的猪肝脏组织为研究对象进行破坏性单轴拉伸实验,并在ABAQUS中对单轴拉伸实验过程进行仿真,通过对比仿真结果与试验数据确定猪肝的超弹性本构方程。以此为基础分别选用尖齿形及波浪齿形夹头对组织的夹持过程进行有限元仿真。结果采用4阶Ogden模型开展拉伸实验的仿真结果与试验数据吻合度较高。组织夹持仿真结果表明,采用尖齿形夹头更容易产生应力集中。结论可以采用4阶Ogden模型描述猪肝的超弹性,并确定相关参数。采用尖齿形夹头更容易造成组织夹持损伤,且组织应力与夹持进给量基本成线性关系。研究结果为手术钳头的设计提供参考。

Hyperelasticity of biological soft tissues and simulation analysis on the clamping process

Objective To determine the hyperelastic constitutive equation of biological soft tissues and study the mechanical responses during the clamping process of biological tissues. Methods The destructive uniaxial tensile test was performed on fresh porcine liver and the uniaxial tension experiment was simulated in ABAQUS. The hyperelastic constitutive equation of porcine liver was determined by comparing the simulation results with the experimental data. Based on this equation, the sharp teeth-shaped and wave-shaped chucks were used to simulate the clamping process. Results The simulation results of the tensile experiment with the 4th-order Ogden model were in good agreement with the experimental data. The results of tissue clamping simulation showed that stress concentration was more likely to occur when the sharp teeth-shaped chuck was adopted. Conclusions The 4th-order Ogden model can be used to describe the hyperelasticity of porcine liver and determine the relevant para-meters. Using the sharp-shaped chuck is more likely to cause tissue clamping damage, and there is a linear relationship between tissue stress and clamping feed distance. These research findings provide references for the design of surgical clamp.