腹腔镜器械与生物组织的接触力学分析

目的 建立生物组织与腹腔镜器械的接触变形模型，进行接触应力应变分析。方法 利用Kelvin-Voigt模型及Hertz接触理论，建立楔形、圆形齿结构的器械与生物组织接触变形模型，分析接触应力及应变随时间变化的情况；并运用有限元分析及生物阻抗测量方法，比较不同器械结构与组织接触后的变形及应力变化情况。结果 不同结构的齿在抓取组织时对组织造成不同的应力应变。楔形齿结构对组织造成的应力最大，圆形齿最小，楔形与圆形混合齿介于两者之间。结论 楔形与圆形混合齿可以有效减少抓钳与组织接触时产生的过载压力，从而能够减小楔形齿对组织造成的伤害，增强圆形齿抓取组织的能力。在临床上，该方法可为腹腔镜器械的安全使用和设计提供重要建议。

Mechanical analysis on laparoscopic instruments when contacting with biological tissues

Objective To establish the contact deformation model of biological tissues contacting with endoscopic instruments, and to make mechanical analysis on contact stress and strain. Methods Based on Kelvin-Voigt model and Hertz contact theory, the contact deformation model of instruments (with both wedge-shaped teeth and cylinder-shaped teeth) contacting with biological tissues was established, and the variation of contact stress and strain changing with time in different endoscopic instruments were obtained through finite element analysis method and bio-impedance measurement. Results Endoscopic instruments with different structures of the teeth could cause different strain and stress on tissues during laparoscopic grasping. The stress of the instrument with wedge-shaped teeth on tissues was largest, while that with cylinder-shaped teeth was smallest, and that of instrument with hybrid structure of wedge-shaped and cylinder-shaped teeth was in between. Conclusions The hybrid structure of wedge-shaped and cylinder-shaped teeth can effectively reduce the peak pressure during laparoscopic grasping, thus prevent less tissue damage caused by wedge-shaped teeth, and enhance the grasping ability with cylinder-shaped teeth. This study provides an important reference for the safety use and better design of laparoscopic instruments in clinic.