一种适用于胶囊机器人的肠道几何参数感知方法

An Intestinal Geometric Parameters Sensing Method for a Capsule Robot

摘要:

胶囊机器人被认为是实现肠道疾病微创诊查最具前景的器件，肠道的几何参数（即半径和厚度）感知对于机器人在未知的肠道环境中实现主动运动具有重要意义，然而现阶段胶囊机器人均不具备这一感知功能；为此提出一种基于扩张机构和薄膜压力传感器的肠道几何参数感知方法；通过在扩张机构末端安装薄膜压力传感器，测量不同扩张半径下肠道的收缩压力，并基于压力值和以本构方程为核心构建的感知模型，实现对肠道初始半径及厚度的感知；搭建实验平台对该感知方法测试发现：针对五段具有不同几何参数的离体猪肠道，可在15s内完成对肠道几何参数感知，对于初始厚度的感知误差范围为[0.084 mm, 0.239 mm]，初始半径的感知误差范围为[0.186 mm, 0.339 mm]。

Abstract:

The capsule robot is a promising medical instrument for a minimally invasive examination of the intestine. Sensing the intestinal geometric parameters (i.e. radius and thickness) is of great significance for its active locomotion in the unknown intestinal environment. But so far, none of a capsule robot is equipped with this sensing function. For this reason, a method for sensing the intestinal geometric parameters based on the expanding mechanism and thin-film pressure sensors is proposed. By installing thin-film pressure sensors on the tips of the expanding mechanism, the contractile forces of intestines in different expanded radius can be measured. And based on the pressure data and a sensing model taking constitutive equation as the core, the initial radius and thickness of intestines can be sensed. An experimental platform is set up to verify the proposed method in five ex-vivo pig intestines with different geometric parameters, and the results show that: the intestinal geometric parameters can be sensed out within 15s, and the sensing errors of the intestinal radius and thickness are in the ranges of [0.084 mm, 0.239 mm] and [0.186 mm, 0.339 mm], respectively.