Fuzzy-Based Feedback Control of a Tip-Mounted Module for Robot-Assisted Endoscopy

Nascent endoscopic therapeutic procedures, such as endoscopic submucosal dissection, enable unparalleled access to and removal of mid-size cancerous neoplasia from within the gastrointestinal tract. However, the remote locations of these lesions often incur substantial distal dexterity which imparts appreciable cognitive loading on the clinician and opens up the possibility of adverse events such as intestinal perforation due to limited dexterity and a lack of sensory feedback. In this work, we introduce a mm-scale, tip-mounted robotic system, EndoMODRA (Endoscopic Module for On-Demand Robotic Assistance), which interfaces with commercially-available endoscopic tools and provides additional dexterity and feedback sensing using on-board actuators and sensors, decoupling tool motion from endoscope motion. Leveraging alternative high-energy-density actuation strategies and monolithic, printed-circuit-inspired manufacturing processes, all actuation and sensing is fully contained within the distally-mounted module, obviating the need for a continuous mechanical transmission to a proximal motor package. We develop a fuzzy-tuned PID/PWM controller for closing the loop distally to enable closed-loop position-controlled trajectory execution using onboard actuation and sensing, realizing fully -distal loop closure in an endoscope-mounted robotic module with no proximal actuation or sensing component. Controller performance is validated on a fully-integrated module with on-board sensing, demonstrating the ability to execute pre-determined trajectories as well as real-time rate-based teleoperation.