Design, Fabrication, and Ex-vivo Validation of an Active Capsule Endoscope

Abstract

Background and AimsActive capsule endoscopy could advance gastrointestinal diagnostics by enabling controlled navigation beyond passive peristalsis. However, current systems are often limited by inefficient propulsion, high power demands, or reliance on external actuation. Herein, we designed, developed and evaluated a novel electromagnetic impact-actuated capsule endoscope incorporating a ferromagnetic rail-enhanced locomotion mechanism. MethodsThe capsule employed an internal electromagnetic actuator comprising a movable coil-armature assembly guided along a ferromagnetic rail and surrounded by permanent magnets. Controlled current pulses generated reciprocating motion and propulsion through momentum transfer. Bench-top testing using a deformable intestinal model assessed locomotion and power consumption. Ex-vivo experiments were subsequently performed in porcine intestine under dry and physiologically simulated wet conditions. Transit speed, power consumption, and system stability were recorded. ResultsBench-top testing demonstrated stable propulsion at speeds up to 8.5 mm/s with a mean power consumption of 84 mW. During ex-vivo evaluation, mean capsule velocities were 1.95 mm/s and 7.2 mm/s under dry and wet conditions, respectively. Average power consumption was 96 mW and 193 mW. The actuator maintained reliable locomotion while preserving a compact system volume of [~]6.19 cm3. Lubricated conditions, representative of the intestinal environment, resulted in enhanced propulsion efficiency despite a concomitant increase in instantaneous power consumption. ConclusionThe electromagnetic impact-actuated capsule demonstrated reliable locomotion in biologically relevant ex-vivo environments while maintaining compact dimensions and moderate power requirements. Ferromagnetic rail-enhanced flux concentration offers a promising propulsion strategy for future actively navigated and therapeutic capsule endoscopy platforms.