Biomechanical Analysis of a Radial Expansion Mechanism of Intestinal Robot Coupling with Hyperelastic Intestinal Wall  

作　　者：LIU Dasheng YAN Guozheng 刘大生;颜国正(Department of Instrument Science and Engineering,School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University,Shanghai,200240,China;Institute of Medical Robotics,Shanghai Jiao Tong University,Shanghai,200240,China)

机构地区：[1]Department of Instrument Science and Engineering,School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University,Shanghai,200240,China [2]Institute of Medical Robotics,Shanghai Jiao Tong University,Shanghai,200240,China

出　　处：《Journal of Shanghai Jiaotong university(Science)》2022年第4期552-560,共9页上海交通大学学报（英文版）

基　　金：the Research Project of Traditional Chinese Medicine of Shanghai Health Committee(No.2020JP012);the Pujiang Talents’Project of Shanghai(No.20PJ1406600);the National Natural Science Foundation of China(No.61673271)。

摘　　要：This paper proposes a new type of radial expansion mechanism by adopting the scissor type telescopic design for intestinal robot to meet the requirements of the intestinal robot’s movement and residence in the intestinal tract.The robot’s maximum expansion radius is up to 25mm,which can well adapt to the intestinal tract with different diameters.At first,the mathematical model of the scissors-type telescopic mechanism(STM)is established to further study its dynamics characteristics by theoretical analysis and simulation.Then,in order to study the coupling effect between the STM and intestinal wall,the strain-energy function of Fung-type is used to establish the constitutive model of intestinal wall.Moreover,aimed at solving the non-convergence problem caused by the selection of material parameters in general Fung-type model,the restrictions for selecting material parameters were given by using positive definite matrix theory.Furthermore,the motion coupling characteristics between the mechanism and intestinal wall were analyzed by using the finite element method.The result shows that if the expansion radius of the STM exceeds a certain value,the intestinal wall may reach its deformation limit,which means that the maximum rotating angle of the three-claw butterfly disc of STM can be decided based on the maximum deformation stress of the intestinal wall.Therefore,it provides a design basis for formulating a reasonable expansion radius in mechanism control to avoid damage to the intestinal wall.

关 键 词：radial expansion mechanism intestinal robot HYPERELASTICITY constitutive model intestinal wall biomechanical analysis 

分 类 号：TP242.6[自动化与计算机技术—检测技术与自动化装置] TH776[自动化与计算机技术—控制科学与工程]