胶囊机器人与小肠组织交互特性研究

For the moment, only the capsule endoscope is applied to the noninvasive diagnosis and therapy of human small intestine. It is of difficulty to drive and control the endoscopes effectively, on account of absence of the research of interaction between the capsule robot and the intestine. Proceeding from the intestinal mechanical constitutive, we research the friction between the capsule and the intestine and the forced deformation of the intestine. Firstly, the notable diversity on the meso-fabrics as well as the rate dependence of the intestinal inner and outer layer, are taken account sufficiently, based on the multilayer anatomical structure. Virtual interlayer is adopted to solve the problem of stress distribution discontinuity at the contact surface. Then the mechanical model of the intestine is established and the residual stress is analyzed. Secondly, the friction model between the capsule and the intestine is established to describe the stick-slip characteristics, based on the LuGre model. Thirdly, the forced deformation of the intestine is researched with the residual stress by the way of finite element simulation. Finally, the multi-axial mechanical experiment will be processed, and the cases on capsule robot researched, to validate our model. This project’s research production will greatly support the capsule robot’ development in theory, and promote the development of gastrointestinal tract tissue biomechanics.

目前，胶囊内窥镜是仅有的适用于人体小肠无创检查的方法。由于缺少其与小肠组织间交互特性的分析，胶囊内窥镜难以实现有效的驱动控制。本项目从小肠组织的力学本构出发，研究胶囊与小肠之间的交互摩擦和小肠的受迫形变特征。首先，在深入分析小肠多层的解剖结构特点的基础上，重点关注非线性弹性在率相关性方面存在的差异，将小肠分为内、外两层进行建模，引入虚拟中间层解决接触面应力分布不连续的问题，最终建立小肠组织整体力学模型并分析其残余应力特征。其次，基于LuGre摩擦模型，建立胶囊在小肠内运动过程中受到摩擦力的解析模型，来描述胶囊运动时的粘滑特征。随后，在考虑残余应力作用条件下，利用有限元仿真手段，建立胶囊在小肠内运动过程中小肠的受迫形变模型。最后，应用多轴实验台和胶囊机器人开展离体实验，进行参数辨识并验证模型有效性。本项目的研究成果将为胶囊机器人的研发提供理论支持，推动消化道组织力学研究的发展。

目前，胶囊内窥镜是仅有的适用于人体小肠无创检查的方法。由于缺少其与小肠组织间交互特性的分析，胶囊内窥镜难以实现有效的驱动控制。.本项目从小肠组织的力学本构出发，研究胶囊与小肠之间的交互摩擦和小肠的受迫形变特征。基于LuGre摩擦模型，建立胶囊在小肠内运动过程中受到摩擦力的解析模型，来描述胶囊运动时的粘滑特征，应用多轴实验台和胶囊机器人开展离体实验，进行参数辨识并验证模型有效性。根据模型预测结果和多次实验结果的比较，波动变化的周期、谷值、峰值的误差分别为6.88%、9.38%和4.78%，模型基本准确。本项目的研究成果将为胶囊机器人的研发提供理论支持，推动消化道组织力学研究的发展。.成功研制了pH检测和图像生理参数复合诊断胶囊机器人系统样机，为本项目模型验证工作提供了样机支持。该胶囊机器人可通过口服进入胃肠道，随着胃肠道的生理蠕动而通过整个胃肠道，无创采集消化道图像，同时检测对应部位的pH值，检测信息通过无线方式发送至体外，从而得到消化道形态、运动与pH值等相关信息，可以实现对胃肠功能的评价以及胃肠疾病的预警和诊断。