Novel Optimization-Based Design and Surgical Evaluation of a Treaded Robotic Capsule Colonoscope

摘要

Robotic capsule endoscopes (RCEs) are being widely investigated to improve the state of various endoscopy procedures. This article presents the novel design of a multi-DOF sensor-enabled RCE for colonoscopies (Endoculus) and evaluates porcine in vivo and ex vivo performance. The novelty of the design includes a custom “double-worm” drive that removes axial gear forces while reducing radial moments, and the full parameterization of gear geometries allows for size minimization via an optimization routine over design constraints. Two independently controlled motors drive micro-pillared treads above and below the device allowing for two-degrees of freedom (2-DOF) skid-steering, even in a collapsed lumen. The Endoculus contains all functionality of a traditional endoscope: a camera, adjustable light emitting diodes (LEDs), channels for insufflation and irrigation, and a tool port for endoscopy instruments (e.g., forceps, snares, etc.). Additionally, the Endoculus carries an inertial measurement unit, magnetometer, motor encoders, and motor current sensors to aid in future autonomy strategies. Porcine surgical evaluation demonstrated locomotion up to 40 mm/s on the colon mucosa, 2-DOF steering, the ability to traverse haustral folds, and functionality of endoscopy tools. This platform will enable future validation of feedback control, localization, and mapping algorithms in the unconventional in vivo environment.