Towards Semi-Autonomous Colon Screening Using an Electromagnetically Actuated Soft-Tethered Colonoscope Based on Visual Servo Control
Yehui Li, Wing Yin Ng, Weibing Li, Yisen Huang, Heng Zhang, Yitian Xian, Jixiu Li, Yichong Sun, Philip Wai Yan Chiu, Zheng Li
Abstract
OBJECTIVE: Conventional colonoscopy using a flexible colonoscope remains two major limitations, including patient discomfort and difficult manipulations for surgeons. Robotic colonoscopes have been developed to conduct colonoscopy in a patient-friendly manner. However, most robotic colonoscopes still maintain nonintuitive and difficult manipulations, which limits their clinical applications. In this paper, we demonstrated visual servo-based semi-autonomous manipulations of an electromagnetic actuated soft-tethered (EAST) colonoscope, which aims to lower difficulties of robotic colonoscope manipulations. METHODS: Kinematic modeling of EAST colonoscope is conducted, with an adaptive visual servo controller established. Template matching method and a lumen and polyp detection model are developed to enable semi-autonomous manipulations, including region-of-interest automatic tracking and autonomous navigation with automatic polyp detection. RESULTS: The EAST colonoscope demonstrates visual servoing with an average convergence time of around 2.5 s and performs disturbance rejection within 3.0 s. Semi-autonomous manipulations were conducted in both a commercialized colonoscopy simulator and an ex-vivo porcine colon to show the efficacy of reducing the user workload compared to manual control. CONCLUSION: The EAST colonoscope can perform visual servoing and semi-autonomous manipulations with the developed methods in both laboratory and ex-vivo environments. SIGNIFICANCE: The proposed solutions and techniques improve the autonomy level of robotic colonoscopes and reduce user workloads, which promotes the development and clinical translation of robotic colonoscopy.